Patent Publication Number: US-2005115186-A1

Title: Iso-truss structure

Description:
BACKGROUND OF THE INVENTION  
      1. The Field of the Invention  
      The present invention relates generally to a three-dimensional structural member which is strong and light-weight. More particularly, the present invention relates to a structural member having a plurality of helical components wrapped about an axis, each having straight segments connected end-to-end in a helical configuration.  
      2. The Background Art  
      The pursuit of structurally efficient structures in the civil, mechanical, aerospace and sports arenas is an ongoing quest. An efficient truss structure is one that has a high strength to weight ratio and/or a high stiffness to weight ratio. An efficient truss structure can also be described as one that is relatively inexpensive, easy to fabricate and assemble, and does not waste material.  
      Trusses are typically stationary, fully constrained structures designed to support loads. They consist of straight members connected at joints at the end of each member. The members are two-force members with forces directed along the member. Two-force members can only produce axial forces such as tension and compression forces in the member. Trusses are often used in the construction of bridges and buildings. Trusses are designed to carry loads which act in the plane of the truss. Therefore, trusses are often treated, and analyzed, as two-dimensional structures. The simplest two-dimensional truss consists of three members joined at their ends to form a triangle. By consecutively adding two members to the simple structure and a new joint, larger structures may be obtained.  
      The simplest three-dimensional truss consists of six members joined at their ends to form a tetrahedron. By consecutively adding three members to the tetrahedron and a new joint, larger structures may be obtained. This three dimensional structure is known as a space truss.  
      Frames, as opposed to trusses, are also typically stationary, fully constrained structures, but have at least one multi-force member with a force that is not directed along the member. Machines are structures containing moving parts and are designed to transmit and modify forces. Machines, like frames, contain at least one multi-force member. A multi-force member can produce not only tension and compression forces, but shear and bending as well.  
      Traditional structural designs have been limited to one or two-dimensional analyses resisting a single load type. For example, I-beams are optimized to resist bending and tubes are optimized to resist torsion. Limiting the design analysis to two dimensions simplifies the design process but neglects combined loading. Three-dimensional analysis is difficult because of the difficulty in conceptualizing and calculating three-dimensional loads and structures. In reality, many structures must be able to resist multiple loadings. Computers are now being utilized to model more complex structures.  
     SUMMARY OF THE INVENTION  
      It has been recognized that it would be advantageous to develop a structural member with enhanced performance characteristics, such as strength reduced weight, etc.  
      The invention provides a three-dimensional structure or structural member, including: 1) at least two, spaced apart, helical components, and 2) at least one reverse helical component attached to the two helical components. The helical and reverse helical components have a common longitudinal axis, but opposing angular orientations about the axis.  
      In addition, each helical and reverse helical component advantageously includes at least four elongate, straight segments rigidly connected end-to-end in a helical configuration forming a single, substantially complete rotation about the axis. Thus, the helical and reverse helical components form a first square-shaped cross section. In one aspect, the structure includes four helical components and four reverse helical components.  
      In addition, the iso-truss structure can include 1) rotated helical components, and 2) rotated reverse helical components, similar to, but rotated with respect to, the helical and reverse helical components above. Thus, the rotated helical and rotated reverse helical components form a second square-shaped cross section, rotated with respect to the first. In one aspect, the structure includes four rotated helical components and four rotated reverse helical components, for a total of sixteen helical components.  
      The various helical components intersect at external nodes and internal nodes. In one aspect, the components form eight internal and eight external nodes. Longitudinal or axial components may extend parallel to the axis and intersect the internal and/or external nodes. In one aspect, the structure includes eight external nodes. It has been found that such an eight node structure has unexpected structural or performance characteristics.  
      In accordance with one aspect of the present invention, the structure can further include an end plate attached at an end of the helical components to attach the helical components to another object. In one aspect, the helical components may be formed of continuous strands of fiber, which may be wound around the end plate. The end plate can include a perimeter with a plurality of indentations to receive the strands of fiber.  
      In accordance with another aspect of the present invention, the structure can further include a connector member attached to the helical components and segments to attach other objects to the helical components and segments. The connector member can include a triangular cross-sectional shape extending through triangular openings formed by the components.  
      In accordance with another aspect of the present invention, the helical and reverse helical components may form an angle therebetween greater than approximately 60 degrees. It has been found that such angles have unexpected structural or performance characteristics.  
      In accordance with another aspect of the present invention, the helical and reverse helical members can be axially and/or laterally flexible, but torsionally stiff. The structure may bend between a first, straight position in which the axes are substantially straight; and a second, arcuate position in which the axes are substantially arcuate. In addition, the structure may compress and/or expand longitudinally. In either case, the structure may store energy, and thus be utilized as a spring member.  
      In accordance with another aspect of the present invention, the structure may be arcuate, and the components may be formed about an arcuate axis. Thus, the arcuate structure may form more complex shapes than a singular, linear structure, and may be better suited for certain applications.  
      In accordance with another aspect of the present invention, the structure may taper. The segments of each helical component may sequentially reduce in length along the axes such that the structural member tapers. Thus, the tapering structure may form more complex shapes than a singular, linear structure, and may be better suited for certain applications.  
      In accordance with another aspect of the present invention, the iso-truss structure may be utilized to hold signs, utility lines, or lights. The iso-truss structure further may be utilized for bicycle frames, aircraft and marine structures, etc.  
      A method for forming an iso-truss structure in accordance with the present invention can include wrapping a fiber around a mandrel in order to create the two helical components and the reverse helical component. A matrix or resin can be added to the fiber and cured. The mandrel may be removed from the structure.  
      The mandrel may include a plurality of heads disposed thereon to receive and hold fiber. The mandrel may be a collapsible or dissolvable mandrel.  
      Additional features and advantages of the invention will be set forth in the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate by way of example, the features of the invention.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an iso-truss structure in accordance with the present invention;  
       FIG. 2  is a side view of the iso-truss structure of  FIG. 1 ;  
       FIG. 3  is a partial perspective view of the iso-truss structure of  FIG. 1 ;  
       FIG. 4  is an end view of the iso-truss structure of  FIG. 1 ;  
       FIGS. 5   a - 5   t  are partial perspective views of the iso-truss structure of  FIG. 1  showing helical components of the present invention;  
       FIG. 6  is a perspective view of another iso-truss structure in accordance with the present invention;  
       FIG. 7  is a side view of the iso-truss structure of  FIG. 6 ;  
       FIG. 8  is an end view of the iso-truss structure of  FIG. 6 ;  
       FIGS. 9   a  and  9   b  are graphs demonstrating performance of iso-truss structures in accordance with the present invention;  
       FIG. 10   a  is an end view of the iso-truss structure of  FIG. 1 ;  
       FIG. 10   b  is a side view of the iso-truss structure of  FIG. 1 ;  
       FIG. 10   c  is an end view of another iso-truss structure of  FIG. 6 ;  
       FIG. 10   d  is a side view of another iso-truss structure of  FIG. 6 ;  
       FIG. 10   e  is an end view of another iso-truss structure;  
       FIG. 10   f  is a side view of another iso-truss structure of  FIG. 10   e;    
       FIG. 11   a  is an end view of a prior art iso-truss structure;  
       FIG. 11   b  is a side view of the iso-truss structure of  FIG. 11   a;    
       FIG. 11   c  is an end view of a prior art iso-truss structure;  
       FIG. 11   d  is a side view of the iso-truss structure of  FIG. 11   c;    
       FIG. 11   e  is an end view of a prior art iso-truss structure;  
       FIG. 11   f  is a side view of the iso-truss structure of  FIG. 11   e;    
       FIG. 12   a  is a perspective view of an end plate in accordance with the present invention;  
       FIG. 12   b  is an end view of the end plate of  FIG. 10   a;    
       FIG. 13  is an end view of an angled plate of the present invention;  
       FIG. 14   a  is a top view of another end plate;  
       FIG. 14   b  is a cross-sectional side view of the end plate of  FIG. 14   a;    
       FIG. 14   c  is a partial cross-sectional view of the end plate of  FIG. 14   a;    
       FIG. 15  is a side view of another end plate in accordance with the present invention secured to an iso-truss structure;  
       FIG. 16  is a top view of the end plate of  FIG. 15 ;  
       FIG. 17   a  is a perspective view of an end connection in accordance with the present invention;  
       FIG. 17   b  is a top view of the end connection of  FIG. 17   a  with an iso-truss structure;  
       FIG. 18   a  is a perspective view of an end connection in accordance with the present invention;  
       FIG. 18   b  is a bottom view of the end connection of  FIG. 18   a  with an iso-truss structure;  
       FIG. 19   a  is a perspective view of an end connection in accordance with the present invention;  
       FIG. 19   b  is a bottom view of the end connection of  FIG. 19   a  with an iso-truss structure;  
       FIG. 20   a  is a perspective view of an end connection in accordance with the present invention with an iso-truss structure;  
       FIG. 20   b  is a side view of the end connection of  FIG. 20   a;    
       FIG. 21   a  is a perspective view of an end connection in accordance with the present invention with an iso-truss structure;  
       FIG. 21   b  is a top view of the end connection of  FIG. 21   a;    
       FIG. 22   a  is a perspective view of an end connection in accordance with the present invention;  
       FIG. 22   b  is a top view of the end connection of  FIG. 22   a;    
       FIG. 23  is a perspective view of a connection in accordance with the present invention;  
       FIG. 24   a  is a perspective view of a connection in accordance with the present invention;  
       FIG. 24   b  is a partial perspective view of the connection of  FIG. 24   a  attaching two iso-truss structures;  
       FIG. 25   a  is a perspective view of another connection in accordance with the present invention;  
       FIG. 26  is a perspective view of an attachment member in accordance with the present invention;  
       FIG. 27  is a perspective view of an iso-truss structure with an attachment member of  FIG. 26 ;  
       FIG. 28   a  is a perspective view of an iso-truss structure with an exterior shell in accordance with the present invention;  
       FIG. 28   b  is a perspective view of the exterior shell of  FIG. 28   a;    
       FIG. 29  is a perspective view of the attachment member of  FIG. 26 ;  
       FIG. 30  is a perspective view of an iso-truss structure with attachment members supporting platforms;  
       FIG. 31  is a perspective view of an iso-truss structure with another configuration of attachment members;  
       FIG. 32  is a side view of a flat member attached to an iso-truss structure in accordance with the present invention;  
       FIG. 33  is a perspective view of flat members attached to an iso-truss structure in accordance with the present invention;  
       FIG. 34   a  is a side view of a flat member attached to an iso-truss structure in accordance with the present invention;  
       FIG. 34   b  is an end view of the flat member of  FIG. 34   a;    
       FIG. 35  is an end view of an attachment of a flat member to an iso-truss structure in accordance with the present invention;  
       FIG. 36  is an end view of an attachment of a flat member to an iso-truss structure in accordance with the present invention;  
       FIG. 37   a  is a top view of an attachment to an iso-truss structure in accordance with the present invention;  
       FIG. 37   b  is a perspective view of the attachment of  FIG. 37   a;    
       FIG. 38   a  is a side view of a tapering iso-truss structure of the present invention;  
       FIG. 38   b  is a side view of another tapering iso-truss structure of the present invention;  
       FIG. 39  is a side view of a flexible iso-truss structure of the present invention shown in a curved configuration;  
       FIG. 40   a  is a side view of an angled iso-truss structure in accordance with the present invention;  
       FIG. 40   b  is a side view of another angled iso-truss structure in accordance with the present invention;  
       FIG. 41  is a side view of a curved iso-truss structure in accordance with the present invention;  
       FIG. 42  is a side view of a circular iso-truss structure in accordance with the present invention;  
       FIG. 43  is a side view of a curved angular iso-truss structure in accordance with the present invention;  
       FIG. 44  is a side view of another curved angular iso-truss structure in accordance with the present invention;  
       FIG. 45  is a side view of another iso-truss structure in accordance with the present invention;  
       FIG. 46  is a detailed perspective view of a braided sock in accordance with the present invention;  
       FIG. 47  is a side view of an integral connector in accordance with the present invention;  
       FIG. 48  is a side view of another integral connector in accordance with the present invention;  
       FIG. 49  is a side view of another integral connector in accordance with the present invention;  
       FIGS. 50 and 51  are side views of a union connector in accordance with the present invention;  
       FIG. 52  is a side view of an elbow connector in accordance with the present invention;  
       FIGS. 53 and 54  are side views of a tee connector in accordance with the present invention;  
       FIG. 55  is a side view of a cross connector in accordance with the present invention;  
       FIG. 56  is a side view of another connector in accordance with the present invention;  
       FIGS. 57 and 58  are schematic exploded views of other attachments in accordance with the present invention;  
       FIG. 59  is a side view of a sign utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 60  is a side view of another sign utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 61  is a side view of another sign utilizing an iso-truss structure in accordance with the present invention;  
       FIGS. 62 and 63  are side views of utility poles utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 64  is a side view of a light pole utilizing an iso-truss structure in accordance with the present invention;  
       FIGS. 65-74  are side views of bicycles with frames utilizing iso-truss structures in accordance with the present invention;  
       FIG. 75  is an exploded view of a bicycle frame utilizing iso-truss structures in accordance with the present invention;  
       FIG. 76  is a perspective view of the bicycle frame of  FIG. 78 ;  
       FIG. 77  is a side view of a mandrel for forming an iso-truss structure in accordance with the present invention;  
       FIG. 78  is a perspective view of a head for a mandrel for forming an iso-truss structure in accordance with the present invention;  
       FIG. 79  is a perspective view of a collapsible mandrel for forming an iso-truss structure in accordance with the present invention;  
       FIG. 80  is a support member utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 81  is a side view of a basketball support utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 82  is a side view of a backpack utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 83  is a perspective view of a boat with a mast or support utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 84  is a side view of a bridge utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 85  is a side view of an oil platform utilizing iso-truss structures in accordance with the present invention;  
       FIG. 86  is a side view of an oil platform utilizing iso-truss structures in accordance with the present invention;  
       FIG. 87  is a cross-sectional end view of a submarine utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 88  is a perspective view of a missile or rocket utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 89   a  is a perspective view of an aircraft utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 89   b  is a cross-sectional end view of the aircraft of  FIG. 89   a;    
       FIG. 90  is a perspective view of a satellite utilizing an iso-truss structure in accordance with the present invention;  
       FIG. 91  is a side view of a water tower utilizing iso-truss structures in accordance with the present invention  
       FIG. 92  is a partial side view of a roof system utilizing iso-truss structures in accordance with the present invention;  
       FIG. 93  is a broken away side view of a kayak utilizing iso-truss structures in accordance with the present invention;  
       FIG. 94  is a partial broken away side view of a rocket utilizing iso-truss structures in accordance with the present invention;  
       FIG. 95  is a side view of an artificial reef utilizing iso-truss structures in accordance with the present invention;  
       FIG. 96  is a partial side view of a drive shaft utilizing iso-truss structures in accordance with the present invention;  
       FIG. 97  is a side view of a shock absorber utilizing iso-truss structures in accordance with the present invention;  
       FIG. 98  is a side view of a flexible joint utilizing iso-truss structures in accordance with the present invention;  
       FIG. 99  is a cross-sectional end view of a pressure vessel or tank utilizing iso-truss structures in accordance with the present invention;  
       FIG. 100  is a side view of a gear system utilizing iso-truss structures in accordance with the present invention;  
       FIGS. 101   a b  are side view of impact barriers utilizing iso-truss structures in accordance with the present invention;  
       FIGS. 102   a  and  b  are cross-sectional end views of impact barriers utilizing iso-truss structures in accordance with the present invention;  
       FIGS. 103   a - c  are end views of iso-truss structures in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION  
      For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.  
      Improved Iso-Truss Structure  
      Some basic features of an iso-truss structure are described in U.S. Pat. No. 5,921,048, issued Jul. 13, 1999, which is herein incorporated by reference. As illustrated in  FIGS. 1-5 , an improved iso-truss structure, indicated generally at  10 , in accordance with the present invention is shown. The structure and geometry of the preferred embodiment of the iso-truss structure  10  may be described in numerous ways. The iso-truss structure  10  includes a plurality of elements or members  12  arranged in a repeating pattern along the length or longitudinal axis  14  of the structure  10 . The structure  10  may be conceptualized and described as a plurality of helical components  20  wrapping about the longitudinal axis  14 . Each helical component  20  includes a plurality of straight segments  22  connected end-to-end in a helical configuration.  
      In one aspect, each helical component  20  advantageously includes at least four straight segments  22  which form a single, substantially complete rotation about the axis  14 . Thus, when viewed along the axis  14 , the four straight segments  22  form a square, or have a square cross-sectional shape, best seen in  FIG. 4 . The helical components  20  may continue indefinitely forming any number of straight segments  22 . The straight segments  22  are oriented at an angle with respect to the axis  14 . Preferably, the straight segments  22  are rigidly connected at their ends to adjacent or sequential segments.  
      In one aspect, the basic structure of the iso-truss structure  10  includes 1) at least two helical components  30  and  32 , and  2 ) at least one reverse helical component  34 , all wrapping around the axis  14 . In another aspect, the basic structure  10  includes 1) four helical components  30 ,  32 ,  36  and  38 , and  2 ) four reverse helical components  34 ,  40 ,  42  and  44 . The helical components  30  and  32  wrap around the axis  14  in one direction, for example clockwise, while the reverse helical component  34  wraps around the axis  14  in the opposite direction, for example counterclockwise. The helical components  30  and  32 , and segments  22  thereof, have a common angular orientation and a common axis  14 . The reverse helical component  34 , and segments thereof, have a similar helical configuration to the helical components  30  and  32 , but an opposing angular orientation. This basic structure  10 , when viewed from the end or axis  14  ( FIG. 4 ), appears as an imaginary tubular member of square cross section.  
      Referring to  FIGS. 5   a - 5   v , the various helical components are shown being individually added to the structure  10  for clarity. The first helical component  30  is shown in  FIG. 5   a . The segments  22  define a square tube  50 , shown in phantom lines. For purposes of  FIG. 5   a , the square tube  50  includes a bottom, top, and left and right sides, or planes. The first helical component  30  includes a first segment  52 , in the left plane; a second segment  54  in the top plane; a third segment  56  in the right plane; and a fourth segment  58  in the bottom plane. The helical component  30  may continue with many more segments. The four segments  22  of the helical component  30  form a single, complete rotation about the axis  14 . Referring to  FIGS. 5   b - 5   d , the second, third and fourth helical segments  32 ,  36  and  38  are shown in bold respectively.  
      Referring to  FIG. 5   e , the first reverse helical segment  34  is shown in bold. The first reverse helical component  34  includes a first segment  60 , in the left plane; a second segment  62  in the bottom plane; a third segment  64  in the right plane; and a fourth segment  66  in the top plane. The reverse helical component  34  may continue with many more segments. The four segments  22  of the reverse helical component  34  form a single, complete rotation about the axis  14 . Referring to  FIGS. 5   f - 5   h , the second, third and fourth reverse helical components  40 ,  42  and  44  are shown in bold respectively.  
      Referring to  FIG. 5   i , all of the helical components  30 ,  32 ,  36  and  38  are shown highlighted. Similarly, referring to  FIG. 5   j , all of the reverse helical components  34 ,  40 ,  42  and  44  are shown highlighted. Referring to  FIG. 5   k , all of the components in the top and right planes are shown highlighted.  
      Referring again to  FIG. 51 , building on the basic structure of the iso-truss structure  10  described above, the iso-truss structure  10  advantageously includes an enhanced basic structure, additionally including 1) rotated helical components, and 2) reverse rotated helical components. The rotated helical components are similar to the helical components, but are rotated with respect to the helical components. Similarly, the reverse rotated helical components are similar to the reverse helical components, but rotated with respect to the reverse helical components. The rotated helical components and the rotated reverse helical components also form a square when viewed along the axis  14  ( FIG. 4 ) which is rotated with respect to the square formed by the helical components  30  and  32  and reverse helical component  34 .  
      Referring to  FIGS. 51-5   u , the various rotated helical components are shown being individually added to the structure  10 , with the helical and reverse helical components removed, for clarity. The first rotated helical component  80  is shown in  FIG. 51 . The segments  22  define a square tube  82 , shown in phantom lines. For purposes of  FIG. 51 , the square tube  52  includes a forward facing, rearward facing, and upper and lower facing sides, or planes. The first helical component  80  includes a first segment  84 , in the forward facing plane; a second segment  86  in the lower facing plane; a third segment  88  in the rear facing plane; and a fourth segment  90  in the upper facing plane. The rotated helical component  80  may continue with many more segments. The four segments  22  of the rotated helical component  80  form a single, complete rotation about the axis  14 . Referring to  FIGS. 5   m - 5   o , the second, third and fourth rotated helical segments  92 ,  94  and  96  are shown in bold respectively.  
      Referring to  FIG. 5   p , the first rotated reverse helical segment  98  is shown in bold. The first rotated reverse helical component  98  includes a first segment  100 , in the forward facing plane; a second segment  102  in the upper facing plane; a third segment  104  in the rear facing plane; and a fourth segment  106  in the lower facing plane. The rotated reverse helical component  98  may continue with many more segments. The four segments  22  of the rotated reverse helical component  98  form a single, complete rotation about the axis  14 . Referring to  FIGS. 5   q - 5   s , the second, third and fourth rotated reverse helical components  110 ,  112  and  114  are shown in bold respectively. All of the components are shown in  FIG. 5   v.    
      Referring again to  FIGS. 1-5 , the iso-truss structure  10  has a plurality of helical components  20 , including: 1) four helical components  30 ,  32 ,  36  and  38 ; 2) four reverse helical components  34 ,  40 ,  42  and  44 ; 3) four rotated helical components  80 ,  92 ,  94  and  96 ; and 4) four rotated reverse helical components  98 ,  110 ,  112  and  114 . Thus, the structure  10  has a total of sixteen helical components  20 .  
      As described above, the straight segments  22  of the helical components  30 ,  32 ,  36  and  38  have a common angular orientation, a common axis  14 , and are spaced apart from each other at equal distances. Similarly, the segments of the reverse helical components  34 ,  40 ,  42  and  44  have a common angular orientation, a common axis  14 , and are spaced apart from each other at equal distances. But the straight segments of the reverse helical components  34 ,  40 ,  42  and  44  have an opposing angular orientation to the angular orientation of the segments of the helical components  30 ,  32 ,  36  an  38 . Again, this structure, when viewed from the end or axis  14 , appears as an imaginary tubular member of square cross section, as shown in  FIG. 4 .  
      The straight segments of the rotated helical components  80 ,  92 ,  94  and  96  have a common angular orientation, a common axis  14 , and are spaced apart from each other at equal distances, like the helical components  30 ,  32 ,  36  and  38 . The segments of the rotated reverse helical components  98 ,  110 ,  112  and  114  have a common angular orientation, a common axis  14 , and are spaced apart from each other at equal distances, like the reverse helical components  34 ,  40 ,  42  and  44 . But the straight segments of the rotated reverse helical components  98 ,  110 ,  112  and  114  have an opposing angular orientation to the angular orientation of the segments of the rotated helical components  80 ,  92 ,  94  and  96 .  
      The rotated helical components  80 ,  92 ,  94  and  96  and the rotated reverse helical components  98 ,  110 ,  112  and  114  are rotated with respect to the helical components  30 ,  32 ,  36  and  38  and reverse helical components  34 ,  40 ,  42  and  44 . In other words, this structure, when viewed from the end or axis  14 , appears as an imaginary tubular member of square cross section, but is rotated with respect to the imaginary tubular member created by the helical and reverse helical components, as shown in  FIG. 4 . Together, the helical, reverse helical, rotated helical, and rotated reverse helical components appear as an imaginary tubular member having an eight-pointed star cross section when viewed from the axis  14 , as shown in  FIG. 4 .  
      Two or more single elements  12  connect or intersect at joints  120  ( FIG. 4 ). The elements  12  may be rigidly connected, flexibly connected, or merely intersect at the joints  120 . A node is formed where intersecting elements  12  are connected. An external node  122  is formed where intersecting elements  12  meet at the perimeter of the structure  10 , best seen in  FIG. 4 . An internal node  124  is formed where intersecting elements  12  meet at the interior of the structure  10 , as seen in  FIG. 4 . The iso-truss structure  10  may be referred to as an eight-node configuration, referring to its eight external nodes  122 , best seen in  FIG. 4 .  
      A bay  128  ( FIGS. 1 and 2 ) is formed by a repeating unit or pattern measured in the direction of the longitudinal axis  14 . A bay  128  contains a single pattern formed by the elements  12 . The structure  10  may comprise any number of bays  128 . In addition, the length of the bay  128  may be varied.  
      An internal angle  130  ( FIG. 3 ) is formed by a plane created by two corresponding elements  12  of a tetrahedron and a plane created by opposing elements of the same tetrahedron.  
      The repeating pattern may be described as a number of triangles or tetrahedrons. The triangles and tetrahedrons are of various sizes with smaller triangles and tetrahedrons being interspersed among larger triangles and tetrahedrons.  
      The structure  10  may be conceptualized as two, imaginary tubular members of square cross section overlaid to form a single imaginary tube with a cross section like an eight-pointed star, as shown in  FIG. 4 . Or, when viewed from the end or longitudinal axis  14 , the structure  10  has the appearance of a plurality of triangles spaced from the axis  14  and oriented about a perimeter to form an imaginary tubular member of polyhedral cross section in the interior of the structure  10 . In the case of the preferred embodiment, eight triangles are spaced about the longitudinal axis to form an imaginary tubular member of octagonal cross section in the interior of the structure  10 .  
      In addition, when viewed from the end or the axis  14 , it is possible to define eight planes parallel with the axis  14 . The planes extend between specific external nodes  122  in an eight-pointed star configuration. The planes are oriented about the axis  14  at 45 degree intervals.  
      Furthermore, within a bay  128 , a ring of triangular grids is formed which are believed to have strong structural properties. This ring of triangular grids circle the interior of the structure  10  in the center of the bay, as shown in  FIG. 4 . It is believed that this strength is due to a greater number of connections.  
      The helical components  30 ,  32 ,  36  and  38  intersect with reverse helical components  34 ,  40 ,  42  and  44  at external nodes  122 . Similarly, rotated helical components  80 ,  92 ,  94  and  96  intersect with rotated reverse helical components  98 ,  110 ,  112  and  114  at external nodes  122 .  
      The helical components  30 ,  32 ,  46  and  38  intersect with rotated reverse helical components  98 ,  110 ,  112  and  114  at internal nodes  124 . Similarly, the rotated helical components  34 ,  40 ,  42  and  44  intersect with reverse helical components  80 ,  92 ,  94  and  96  at internal nodes  124 .  
      The helical components  30 ,  32 ,  36  and  38  and rotated helical components  80 ,  92 ,  94  and  96  do not intersect. Likewise, the reverse helical components  36 ,  40 ,  42  and  44  and rotated reverse helical components  98 ,  110 ,  112  and  114  do not intersect.  
      In addition to the plurality of helical members, the structure  10  also may have eight internal axial members  132  ( FIGS. 2 and 4 ) located in the interior of the structure  10  and intersecting the plurality of helical members  20  at internal nodes  120 . The axial members  132  are parallel with the longitudinal axis  14 .  
      The external and internal nodes  122  and  124  may form rigid connections, or the components may be rigidly connected together. In addition, the axial members  132  may be rigidly coupled to the components at the internal nodes  124 . The components can be made from a composite material. The helical configuration of the structure  10  makes it particularly well suited for composite construction. The components are coupled together as the fibers of the various components overlap each other. The fibers may be wound in a helical pattern about a mandrel following the helical configuration of the member, as described in greater detail below. This provides great strength because the segments of a component are formed by continuous strands of fiber. The elements or components may be a fiber, such as fiber glass, carbon, boron, basalt or Kevlar (aramid), in a matrix, such as a thermoset (epoxy, vinyl ester, etc.), or even a thermoplastic (polyester, polypropylene, PVC, etc.). In addition, an additive may be included in the resin or matrix, such as UV protectors, or chemical repellents.  
      Alternatively, the structure  10  may be constructed of any suitable material, such as wood, metal, plastic, or ceramic and the like. The elements of the member may consist of prefabricated pieces that are joined together with connecters at the nodes  122 . The connector has recesses formed to receive the elements. The recesses are oriented to obtain the desired geometry of member  10 .  
      It is believed that the multiple symmetric and highly redundant nature of the structure  10  provides an attractive, efficient, and damage tolerant structure, with the three-dimensional configuration of the structure  10  providing substantial resistance to local buckling. The structure  10  incorporates stable geometric forms with members that spiral in a piecewise linear fashion in opposing directions around a central cavity. The helical and longitudinal members are repeatedly interwoven, yielding a highly redundant and stable configuration.  
      In addition, the structure  10  takes advantage of the mechanical properties of continuous fiber in the primary load paths. The load is transferred through beam segments to the intersections, where it disperses through other beam segments. Each member carries primarily axial loads, taking full advantage of the inherent strength and stiffness of continuous fiber-reinforced composites. The helical members primarily carry the torsion and transverse shear loads and stabilize the longitudinal members against buckling when loaded in flexure or axial compression, while the longitudinal members primarily carry the axial and flexural loads and stabilize the helical members against buckling when loaded in torsion or transverse shear. Multiple interweaving of the longitudinal and helical members at the joints or nodes provides a strong interlocking mechanism to enable this type of interdependent three-dimensional stabilization.  
      Furthermore, the highly redundant nature of the structure  10  makes it very damage tolerant. Removal of a single member results in only fractional degradation of the overall structure. In fact, removal of a complete node reduces the effective properties by approximately 1/N, where N represents the number of nodes in a single cross-section. This damage tolerance capability provides a significant performance advantage over traditional shell structures.  
      Failure of composite iso-grid structures typically displays a more ductile overall behavior than is generally observed in advanced composite structures. Although the initial response is still linear elastic to the ultimate load, the subsequent behavior after damage initiation is generally nonlinear. In compression, this nonlinearity generally includes a roughly 1/N drop in load each time the members through one of the nodes fail. In flexure, the failure is less ductile, since the load is concentrated in fewer members.  
      Failure initiation under one load type causes only minimal reduction in strength when loaded in another direction, although the stiffness may be more adversely affected. Furthermore, failure of the principal load carrying members has little or no effect on the ability of the secondary load carrying members to resist simple loading. Failure of one bay in compression has little effect on the torsion capacity of the structure, although the corresponding toughness is reduced. In other words, local failure of the primary members has little effect on the capacity of the secondary members.  
      From the basic configuration of the structure  10  described above, several alternative configurations are possible with the addition of additional members. Referring to  FIGS. 6-8 , external axial members  140  may also be located at the perimeter of the structure  10  and intersect the plurality of helical members  20  at the external nodes  122 . The axial members  140  are parallel with the longitudinal axis  14 . In addition, perimeter members  144  may be located around the perimeter between nodes  122  that lay in a plane perpendicular to the longitudinal axis  14 . The perimeter members  144  form a polyhedron when viewed from the axis  14 , as shown in  FIG. 8 .  
      The perimeter members  144  may be located around the perimeter of the structure  10  between nodes  122  on a diagonal with respect to the longitudinal axis  14 . These diagonal perimeter members may be formed by segments of additional helical components wrapped around the perimeter of the plurality of helical components  20 . The diagonal perimeter members may extend between adjacent nodes  122 , or extend to alternating nodes  122 . Such perimeter members may form another iso-truss structure about the first, or a double iso-truss structure. Such a configuration creates a relatively smooth outer surface or supporting structure that simplifies application of an outer skin for cosmetic of structural purposes. The double iso-truss structure also provides enhanced stiffness per unit weight.  
      As stated above, the improved iso-truss structure of the present invention preferably includes sixteen helical components which each include four segments forming a full rotation about the axis  14  to form square cross sections, and may be referred to as an eight node structure. A side-by-side comparison of the eight and six node configurations is shown in  FIGS. 10   a - f  and  11   a - 11   f , respectively. The eight node structure  10  is shown in  FIGS. 10   a  and  10   b , while the six node structure is shown in  FIGS. 11   a  and  11   b.    
      External axial members  140  and perimeter members  144  have been added to the structures shown in  FIGS. 10   c  and  10   d  for the eight node structure, and  FIGS. 11   c  and  11   d  for the six node structure. As stated above, the external axial members  140  and perimeter members  144  may form another iso-truss structure about the first, or a double iso-truss structure. The internal axial members have been removed from the structure shown in  FIGS. 10   e  and  10   f  for the eight node structure, and  FIGS. 11   e  and  11   f  for the six node structure.  
      The eight node configuration results in the structure  10  having parallel sides, which makes the structure more square and better suited for applications which prefer square geometries. For example, the eight node configuration fits better in a box, due to its parallel and perpendicular sides, permitting greater suitability for numerous internal stiffening applications where the dimensions of the structure are constrained.  
      In addition, the increased number of nodes increases the angle between adjacent segments or members of each helical component. It will be appreciated that with a six node configuration, each helical component would have three segments or members forming a complete rotation, or a triangle, with a relatively sharp angle between adjacent segments or members. Such sharp angles act as points of stress concentration, and may be subject to failure. With an eight node configuration, however, each helical component has four segments or members forming a substantially complete rotation, or a square, with relatively wider angles, which may have reduced stress and failure. Furthermore, the nodes may be more rounded to further reduce stress concentration. The eight node configuration, with wider angles, facilitates rounded nodes, and thus reduces stress concentrations.  
      In addition, the eight node configuration has more unobstructed internal space (free volume) as a percentage of the total cross-sectional area, permitting easier fabrication and yielding more internal volume for non-structural purposes than the six node configuration.  
      Performance Characteristics  
      Referring to  FIGS. 9   a - 9   f , the performance of the iso-truss structure  10  of the present invention is shown with respect to other configurations. As indicated above, the iso-truss structure  10  of the present invention includes eight external nodes  122 , and may be referred to as an eight node structure. In addition, the iso-truss structure  10  of the present invention includes sixteen helical components which each include four segments forming a full rotation about the axis  14  to form square cross sections. A basic structure disclosed in U.S. Pat. No. 5,921,048 includes only twelve helical components, each with only three straight segments forming triangular cross sections, and thus includes only six external nodes. A side-by-side comparison of the eight and six node configurations is shown in  FIGS. 10   a - f  and  11   a - 11   f , respectively.  
      Referring to  FIG. 9   a , the bending strength of various configurations of structures are shown. In particular, the bending strength of several structures is shown which have six, eight, nine, ten and twelve nodes. It can be seen from the figure that an eight-noded structure has the surprising and unexpected result of significantly increasing the bending strength. Referring to  FIG. 9   b , the torsional strength of various configurations of structures with various numbers of nodes is shown. Again, it can be seen from the figure that an eight node structure  10  has the surprising and unexpected result of significantly increasing the torsional strength of the structure  10 . While increasing the number of nodes beyond eight causes an increase in both bending and torsional strength, the increase is not nearly as significant as the increase from six to eight nodes.  
      Angular Configuration  
      Referring again to  FIGS. 2 and 3 , an angle  130  is formed between a helical component  30  and a reverse helical component  34 , or the segments thereof. Preferably, this angle  130  is greater than or equal to 45 degrees; more preferably greater than 60 degrees; and most preferably greater than or equal to 75 degrees. Referring again to  FIG. 9   a , it can be seen that the bending strength surprisingly and unexpectedly increases a significant amount as the angle  130  between the helical and reverse helical components  30  and  34  is increased. Similarly referring to  FIG. 9   b , the torsional strength of the structure  10  also surprisingly and unexpectedly increases a significant amount when the angle  130  is 75 degrees. The torsional properties appear to be greatest at an angle  130  of approximately 90 degrees.  
      From the figures, it can be seen that the bending and axial (tension) properties of the structure improve as the angle  130  increases. Other properties, however, such as buckling and torsion appear to be reduced as the angle increases. One problem with tubular composite structures is their poor bending properties, or they bend too easily. The structure of the present invention, however, and the increased angle, demonstrates improved, or stiffer, bending properties.  
      End Connections  
      Referring to  FIGS. 12   a  and  b , an end plate  120  is shown for attaching the iso-truss structure  10  to other structures and objects, and/or for facilitating manufacture of the iso-truss structure  10 . The end plate  120  is attached to an end of the helical components  20  in order to attach the helical components and the structure  10  to another object. The end plate  120  includes a plurality of apertures  121  through which bolts or the like may be used to secure the end plate  120 , and thus the iso-truss structure  10 , to another object. In addition, the end plate  120  includes a perimeter  122  with a plurality of indentations  123   a . The indentations  123   a  may receive the helical and/or external axial components, or the strands of fiber forming the helical or external axial components. For example, strands of fiber may be wound around the end plate through the indentations  123   a , such that the end plate  120  is integrally formed with the iso-truss structure  10 , thus providing a strong attachment between the end plate  120  and the iso-truss structure  10 . A strand of fiber may pass through one indentation  123   a , wrap around the end plate  120 , and pass back through another indentation  123   a . Furthermore, the end plate  120  may include a center aperture  124  through which a mandrel is received during the manufacturing process, as discussed in greater detail below. Further indentations  123   b  may also be provided for receiving the internal axial members  132 , or the strands of fiber comprising the internal axial members.  
      Referring to  FIG. 13 , an angled end plate  125  may be provided for attaching to the iso-truss structure  10  at an angle with respect to the longitudinal axis  14 . The angled end plate  125  is similar in many respects to the end plate  120  except that the angled end plate  125  is elongated in one direction to accommodate its attachment at an angle. Such an angled end plate  125  may be used to attach two iso-truss structures together at an angle. For example, the angled end plate  125  may be configured to attach to an iso-truss structure at a 45 degree angle. Thus, two iso-truss structures may be connected by angled end plates  125  to form a 90 degree angle there between.  
      Referring to  FIGS. 14   a - c , another end plate  126  is shown for attaching to the structure  10  in order to attach the structure to another object. The end plate  126  includes a groove or slot  127  for receiving the structure. Preferably, the groove  127  is octagonal for receiving the inner portion of the structure. The groove or slot  127  can be formed about the plate  126  near the edge or perimeter creating a perimeter wall  128 . The perimeter wall  128  can be slotted  129  to form a plurality of flaps or fingers  130 , which may be flexible to bend outwardly to receive the structure, and resilient to bend back inwardly once the structure is received, such that the structure “snaps” into the groove  127  between the plate  126  and fingers  130 .  
      Other grooves or indentations  131  may be formed in the plate  126  or fingers  130  and located and oriented to receive the various segments of the structure therein, such that the fingers  130  “snap” around the various segments to hold the structure to the plate  126 . Holes  132  can be formed through the fingers  130 , the groove  127 , and into the plate  126  to receive bolts or screws to further secure the structure in the groove  127 . The holes  132  are located such that the bolts or screws pass through the structure around various segments thereof. Such a configuration has the advantage that the structure can be snapped into the plate.  
      Referring to  FIGS. 15 and 16 , another end plate  136  is shown for attachment to the structure  10 . A plurality of U-shaped bolts or members  137  extend around various segments or nodes of the structure  10  and are secured to the plate  136  to secure the structure to the plate. The U-shaped bolts or members  137  may be angled such that bolts or members  137  extend radially through the structure  10  and then angle longitudinally or axially towards the end plate  136 . Holes may be formed in the plate  136  for receiving the bolts or members  137 , which may be secured by nuts threaded onto the ends thereof. The bolts or members  137  may be located outside the structure  10 , as shown, or may be located inside. In addition, the bolts or members  137  may engage the structure  10  at external nodes  122 , and engage both helical members, and external axial member  140 . Such a configuration may be less expensive to fabricate.  
      Referring to  FIGS. 17   a  and  b , another end connector  140  is shown which includes a base  141  with a plurality of fingers  142  which extend into the structure  10 , and are received within the openings formed between the various segments of the structure  10 . The base  141  may be annular, with the fingers  142  disposed around the annular base  141  and extending longitudinally, or axially. Preferably, the base  141  is sized to fit within the central cavity or space between the segments or helical members. In addition, the connection  140  preferably includes eight fingers  142 , to extend into the eight triangular openings or voids formed between the segments of the structure  10 . A center ring  143  is disposed in the central cavity or space, and is attached to the fingers  142  by fasteners  144 , such as bolts. Thus, the center ring  143  and fasteners  144  secure the fingers  142  and base  141  to the structure  10 . Other objects may be secured to the base  141  to attach such objects to the structure  10 . The configuration of the connection  140  allows the base  141  and fingers  142  to be easily slid into the end of the structure, and attached to the center ring  143  by the fasteners  144 . In addition, the connection  140  is entirely disposed within the circumference or perimeter of the structure  10  such that the connection  140  does not protrude therefrom. The fingers may be flexible and resilient to be bent inwardly as the fasteners are tightened, gripping the structure.  
      Referring to  FIGS. 18   a  and  b , a similar connection  146  is shown in which a C-clamp type fastener  147  is utilized in place of the center ring  143  described above. In addition, L-shaped members  148  are secured to or protrude from the fingers  142  and extend into the central cavity or space. The C-clamp  147  surrounds the angled portion of the L-shaped members  148 , securing them together, and thus securing the fingers  142  and base  141  to the structure  10 . Such a configuration of the connection  146  allows the fingers  142  to bend inwardly towards the center as the C-clamp  147  is tightened. Thus, the fingers  142  may grip the structure  10 .  
      Referring to  FIGS. 19   a  and  b , a similar connection  150  is shown in which the fingers  142  are paired together, or connected in pairs. An L-shaped member  151  is attached to, or extends from, each pair towards the middle of the central cavity or space in the structure  10 . Opposing L-shaped members  151  are coupled together by fasteners  152 , such as bolts. The fasteners  152  may be tightened, drawing the L-shaped members  151 , and thus the fingers  142 , inwardly. Thus, the fingers  142  may grip the structure  10 .  
      Referring to  FIGS. 20   a  and  b , another end connection has an end plate  154  with a plurality of fingers  155  extending therefrom in the axial or longitudinal direction. Preferably, the fingers  155  are sized, shaped and located to extend into the openings between the segments of the structure  10 . Thus, the connection preferably includes eight fingers  155  with triangular cross-sectional shapes to fit snugly or completely in the openings between the segments. In addition, the connection includes a ring member  156  disposed about the exterior of the structure  10 , preferably about a narrow portion or the inner nodes. The fingers  155  and ring member  156  are attached, such as by fasteners, to secure the base plate  154  to the structure  10 . The fingers  155  may have slots or indentations for receiving the ring member  156 . In addition, the ring member  156  may be segmented, or formed of more than one piece, in order to dispose the ring member  156  about the exterior of the structure  10  at a narrow portion.  
      Referring to  FIGS. 21   a  and  b , a similar connection is shown in which a plurality of retaining members  157  are attached to the fingers  155  to retain the structure  10  on the fingers  155  and base plate  154 . The fingers  155  can include slots, holes, or the like, for receiving the retaining members  157  therethrough. The retaining members  157  can extend through the fingers, and the segments of the structure  10 . Thus, the fingers  155  and base plate  154  may be slid onto the end of the structure  10 , and the retaining members  157  disposed through the fingers  155  and structure  10 , to secure the base plate  154  to the structure.  
      Referring to  FIGS. 22   a  and  b , another end connection  160  is shown with a base  161  and a plurality of fingers  162 . The base  161  may be annular, and sized to extend around the exterior of the structure  10 . The fingers  162  may extend inwardly from the annular base  161  to be received in the spaces between the segments of the structure  10 . The base  161  preferably is octagonal to receive the structure therein, and to extend completely around the circumference or perimeter of the structure  10 . Other objects may be secured to the exterior of the structure  10  by attaching such objects to the base  161 .  
      Referring to  FIG. 23 , a similar end connection  164  is shown  164  with a base  165  which extend only partially about the circumference or perimeter of the structure  10 . Again, other objects may be secured to the structure  10  by attaching such objects to the base  165 .  
      Referring to  FIGS. 24   a  and  b , another type of end connection  170  is shown for attaching two structures  10  and  171  together, preferably in an end-to-end configuration. Such a connection  170  may be useful in assembling multiple structures  10  and  171  together to form a larger structure. The connection  170  includes opposite first and second ends  172  and  173  configured to engage and couple to the first and second structures  10  and  171 , respectively. The connection  170  includes an elongated, axial member  174  configured to extend along the axis or longitude of the structures  10  and  171 . The axial member  174  preferably is segmented into first and second portions adjustably attached together by an adjustable attachment member  175 . The proximal ends of the first and second portions can be threaded, while the attachment member  175  can have opposite threaded openings receiving the proximal ends. Thus, turning the attachment member  175  either draws the first and second portions together, or further separates them.  
      The ends  172  and  173  are configured to engage and attach to the structures  10  and  171 , respectively. Each end  172  and  173  preferably is formed into a hook-like configuration for securing to the segments of the structures. The ends  172  and  173  can include an angled, U-shaped member  176  for engaging the segments of the structures. Thus, members  176  extend from the ends inwardly towards the structures, and then angle longitudinally or axially, to form a hook. In addition, the U-shaped members  176  may extend along either side of an axial member. Thus, the U-shaped members  176  can be hooked to the structures, and the first and second portions of the axial member  174  drawn together by rotating the attachment member  175 , in order to draw the first and second structures  10  and  171  together in a secure or attached relationship.  
      Referring to  FIG. 25 , a similar attachment  178  is shown in which hoops or loops  179  are formed at the ends  172  and  173  for surrounding segments of the structures  10  and  171 . The hoops or loops  179  can be formed by angled U-shaped members with ends received in brackets at the ends  172  and  173  of the axial member  174 .  
      Intermediate Connections  
      In addition to connecting the iso-truss structure  10  at its ends, it may be necessary or desirable to attach other objects at an intermediate point of the iso-truss structure. Referring to  FIG. 26 , an attachment member  180  may be provided for attaching to the iso-truss structure  10  at an intermediate location. The attachment member  180  may have a triangular cross section, or a portion with a triangular-like cross section. Thus, the triangular cross section of the attachment member  180  may be received through a triangular opening in the iso-truss structure  10 , as shown in  FIG. 27 . Preferably, the triangular shape of the attachment member  180  matches the size and triangular shape of the openings through the structure  10 , to form a snug, or firm fit. A plurality of grooves  182  may be formed in the attachment member for receiving the helical components. Therefore, other objects may be attached to the attachment member  180  in order to attach the objects to the iso-truss structure  10 . For example, a pair of attachment members  180  may extend through the structure  10 , to support other objects, such as cross members of utility poles to support utility lines, etc.  
      Referring to  FIG. 27 , the ends of the attachment member  180  may have indentations  184  formed in the triangular cross section to receive and facilitate the use of fasteners  185 , such as bolts. The indentations  184  create a flat flange  186  for the fasteners  185 .  
      As stated above, various other objects may be attached to the structure  10 , or the attachment members  180 . Referring to  FIGS. 28   a  and  b , an exterior shell  190  may be attached to the structure  10 . The shell  190  may be utilized to protect the structure  10  or as a platform for attaching other objects to the shell  190 , and thus to the structure  10 . The shell  190  can have any appropriate shape. The shell  190  may be octagonal, or have an octagonal cross-section, to match the exterior or perimeter of the structure  10 . Attachment members  191 , similar to those described above, extend through the structure  10 , and can have triangular cross-sections. The shell  190  may be provided in lateral or radial portions, such as first and second halves which each extend longitudinally or axially along the length of the structure  10 . Each half of the shell  190  can be attached to the ends of the attachment members  191 . For example, apertures may be formed in the shell  190 , and bores formed axially in the ends of the attachment members  191 , to receive fasteners, such as bolts, which extend through the apertures an bores to secure the shell  190  to the attachment members  191 . The shell  190  may prevent climbing on the structure  10 , protect the structure  10 , or have various other objects attached thereto.  
      Referring to  FIG. 29 , it will be noted that the attachment members  180 , as described above, may be configured in groups or pairs. In addition, the pairs of attachment members  180  may be oriented to point towards one another, forming an hour-glass profile, or away from one another, forming a diamond shaped profile. Furthermore, the attachment members  180  may be grouped and oriented to extend from opposite sides, and/or radiate outwardly on more than one or two sides, such as four orthogonal sides, as shown.  
      Brackets  193  can be configured to surround the ends of the pair of attachment members  180 . Various objects may be attached to the brackets  193 , such as eyes for suspending other objects, as shown.  
      Referring to  FIG. 30 , platforms  195  may be attached to the pairs of attachment members  180 .  
      Referring to  FIG. 31 , multiple attachment members  180  can be configured to extend through the structure  10  in a square configuration, allowing attachment from multiple sides. Each attachment member  180  can include an elongated protrusion  194 , and be attached to adjacent members.  
      The attachment members described above preferably are triangular to match the openings extending through the structure  10 . Referring to  FIG. 32 , flat attachment members  200  may extend through the openings in the structure. The flat attachment members  200  can include indicia and can be utilized as signs, or can be utilized as platforms. U-bolts  201  can be used to attach the flat attachment member  200  to segments, such as the exterior axial members.  
      Referring to  FIG. 33 , other flat members  206  can be attached to the exterior of the structure  10 . Hooks  207  can be formed on one side of the flat members  206  for engaging or hooking to the segments of the structure  10 . Other object can be attached to the other side of the flat member  206 , or indicia may be provided on the other side.  
      Referring to  FIGS. 34   a  and  b , flat members  210  can be attached to the exterior of the structure  10  utilizing attachment members  211 , similar to those described above. One or more attachment members  211  may extend through the structure  10  near the exterior. Fasteners  212 , such as U-bolts, can extend around the attachment members  211  and attach to the flat member  210 , such as by extending through apertures therein.  
      Referring to  FIG. 35 , attachment members  216  can extend through the structure  10  and attach directly to a flat member  217 . The attachment members  216  may be configured in a block U-shaped configuration to engage more of the structure  10 . Alternatively, rounded U-shaped attachment members  218  may extend through the structure  10 , as shown in  FIG. 36 .  
      Many of the attachment members described above have been described as extending through the structure  10 . Referring to  FIGS. 37   a  and  b , attachment members  220  may extend into the structure  10 , and be coupled in the central cavity or space, without extending entirely through the structure  10 . The members  220  may be provided with flanges that are attached with a fastener.  
      In addition, the attachment member may have other cross sectional shapes and be configured to extend through other cross sectional openings in the structure. For example, the attachment member may have a quadrilateral cross sectional shape and extend through a quadrilateral opening in the structure.  
      One or more nodes may be removed or left out to facilitate attachment of an object to the structure. For example, leaving out one node presents a flatter side. In addition, opposite nodes can be left out for flatter, opposite sides, for an attachment through the structure.  
      Tapering Iso-Truss Structure  
      Referring to  FIGS. 38   a  and  38   b , iso-truss structures are shown which are similar to the iso-truss structure  10  described above, but taper in one or more directions. Referring to  FIG. 38   a , an iso-truss structure  230  tapers from a wider first end  231  to a narrower second end  232 . The individual segments  12  which form the helical components of the structure  230  vary in length from being longer at the first end  231  to shorter at the second end  232 , such that the entire structure  230  tapers. The helical components may continue to wrap around the longitudinal axis with the same angular orientation. The structure  230  may also include axial members  233  which are not parallel with the longitudinal axis  14  of the structure  230 .  
      Referring to  FIG. 38   b , another iso-truss structure  234  may have narrow ends  235  and  236  and a wider middle  237 . Again, the individual segments  12  forming the helical components may vary in length from longer at the middle  237  to shorter at the ends  235  and  236 . It is of course understood that the structure may taper in the middle, and thus have wider ends and a narrower middle.  
      Flexible or Bendable Iso-Truss Structure  
      Referring to  FIG. 39 , a flexible or bendable iso-truss structure  240  is shown which is similar in many respects to the iso-truss structure  10  described above, but does not include any axial members. Again, the individual components  12  and the helical members may be rigidly interconnected, but the segments  22  can include a degree of flexibility. Thus, the iso-truss structure  240  may bend laterally between a first straight configuration, similar to  FIG. 5   t , and a second curved configuration as shown in  FIG. 39 . In the straight position, the structure  240  includes a straight longitudinal axis  14 , as in  FIG. 5   t . Referring to  FIG. 39  and the curved position, the segments and helical components bend and flex such that the entire structure  240  bends laterally about an arcuate or curved axis  242 .  
      The lack of the longitudinal components allows the structure  240  to bend or flex in a lateral direction. It has been discovered, however, that although the structure  240  is capable of bending in a lateral direction, the structure  240  continues to maintain its torsional stiffness, or resist rotation about the longitudinal axis  14 .  
      In addition, a similar structure also can compress and/or expand axially or longitudinally. Thus, the structure may expand and/or compress, preferably storing energy, so that the structure can function as a spring member.  
      Angled Iso-Truss Structures  
      Referring to  FIG. 40   a , a structural member  250  is shown which is similar in many respects to the structural member  10  described above, but includes two sections  252  and  254  which form an angle with respect to one another. For example, the two sections  252  and  254  may form a right angle. In addition, the two sections  252  and  254  can be integrally formed, or the helical components of one section  252  continue to form the helical components of the second section  254 . Thus, the structure  250  forms a continuous angled structure which may be stronger than a separate structure formed with some type of connection. Such an arrangement or configuration may be utilized in constructing more complicated structures.  
      The structure  250  may have exterior axial members  256  attached to the external nodes  122 . Alternatively, a structure  258  may be angled, but without exterior axial members, as shown in  FIG. 40   b.    
      Curved Iso-Truss Structures  
      Referring to  FIG. 41 , a curved iso-truss structure  270  is shown which is similar to the iso-truss structure  10  described above, but has a curved or arcuate longitudinal axis  272 . The helical components forming the arcuate structure  270  have segments of different lengths. For example, the inside segments  274  on the inside of the curve can be shorter than the outside segments  276  on the outside of the curve. In addition, the axial members  278  are also curved and parallel with the curved longitudinal axis  272 . Such curved structures  270  may produce less stress than sharp angles.  
      Referring to  FIG. 42 , a circular iso-truss structure  280  may be formed. The circular structure  280  may be continuous as shown. The circular structure may have exterior axial members.  
      The curved or circular configurations of the iso-truss structure are believed to impart the same structural advantages of the straight iso-truss structures to the curved and circular structures.  
      Referring to  FIG. 43 , an iso-truss structure  300  may include a curved portion  302  joining to other portions  304  and  306  which may be straight. Such a configuration is similar to the sharp angular configuration shown in  FIG. 40   b , but provides curvature at the connection of the sections  304  and  306 . The curved section  302  is similar to the curved structure  270  described above. Such a configuration can be utilized for more complex structures as described in further detail below. Such curved portions may be stronger and prevent stress concentrations of sharper angles.  
      The structure may have a broad curved section as shown in  FIG. 43 , or may have a sharper curved section as shown in  FIG. 44 . Referring to  FIG. 44 , a structural member  320  is shown in which the structure  320  forms a right angle bend around a external node  324 . Thus, a number of helical components may pass through the node  324 . The helical components may be continuously formed through the curve. The structure may include external axial components  326 .  
      Referring to  FIG. 45 , an iso-truss structure  330  may be formed with multiple bends or curvatures  332 , and/or with more complicated or sharp curvatures. For example, a structure may be formed with multiple right angle curvatures. As another example, a structure may be formed with sharp curvatures, broad curves, or with multiple different curvatures, like an S-shape.  
      Braided Pre-Form  
      As stated above, many of the above-described structures may be formed by resin impregnated fibers, to form rigid structures. Many of the above-described structures may also be provided in a braided pre-form configuration. The structures may be formed by winding strands of fiber together. In addition, additional strands of fiber may be wrapped around segments to hold the fibers together. The strands of fiber, however, without their resin, remain flexible, and may be collapsed and expanded as desired. Thus, such a braided pre-form may be collapsed or substantially compacted into a small area for transportation, etc. The braided pre-form may then be expanded and impregnated with resin to form the desired structure.  
      Referring to  FIG. 46 , the long fibers forming the segments or helical members, may be sheathed in a braided sock  348  disposed around the fibers. Such a sock  348  maintains the internal long fibers together, to prevent tangling, etc.  
      In addition, the fibers or segments can be twisted to compact the fibers. Furthermore, the segments, or fibers thereof, can be wrapped, such as in a spiral, with other fibers for compaction.  
      Integral Connectors  
      Referring to  FIG. 47 , the structure  10  can be provided at its ends with connectors  350 . Such connectors  350  can be integrally formed with the structure  10 , such as by fiber reinforced resin extending continuously between the structure  10  and the connectors  350 . The connectors  350  are configured to attach or couple the structure  10  to mating connectors or structures. Thus, the connectors  350  may be formed as protrusions or indentations, such as male and female connectors, for mating with opposite indentations or protrusions, respectively, or female and male connectors.  
      The connectors  350  can have a circular cross-sectional shape, similar to cylindrical composite tubes, and be received within a circular opening in a receiving connector, as described below. The connector  350  may be threaded  353 , or have external threads, as shown in  FIG. 49 , and threadedly mate with internal threads of a receiving connector, described below. The connectors  350  may be protrusions, or male connectors, as shown, or may be indentations, or female connectors. Alternatively, the connectors  350  can have a hexagonal cross-sectional shape  356 , or an octagonal cross-sectional shape, for mating with a similar shaped connector  357 , as shown in  FIG. 48 . It is of course understood that the connectors can have any appropriate shape, including for example, square or triangular.  
      Various shaped members may be provided for connecting structures. For example, union  360  or  361  can have opposing openings for receiving connectors  352  or  356  from two structures, to couple the structures together in an end-to-end configuration, as shown in  FIGS. 50 and 51 . An elbow  362  can have an angled configuration, such as a 90 degree angle, to coupled two structures together at an angle, as shown in  FIG. 52 . It is of course understood that any appropriate angle can be provided. A tee  364  or  357  can have a T-shaped body for coupling a structure at an angle, as shown in  FIGS. 53 and 54 . A cross  366  can have four openings, as shown in  FIG. 55 . Other connectors may connect the structures to a base  354 , as shown in  FIG. 56 .  
      Other Attachments  
      Other attachments also are possible. Referring to  FIGS. 57 and 58 , for example, a plurality of members  380  or  381  extend through the structure transverse to one another. The members  380  and  381  can include grooves  382  for mating with one another in an overlapping relationship. For example, for a six-node structure, three members  380  can extend through the structure and mate as they overlap one another. Holes  384  may be formed in the members  380  for receiving fasteners, such as bolts, which extend through the members  380  and into a base  386  or  387 . Thus, the members  380  extend through the structure, attaching the structure to the plate  386 .  
      Signs  
      Referring to  FIGS. 59-61 , such iso-truss structures as described above may be used to hold signs. Referring to  FIG. 59 , a straight iso-truss structure  400  may be vertically oriented and have a first end  402  secured to a support surface, such as the ground, and an opposite second end elevated above the first end  402 . A sign  406  may be attached to the upper-end  404  of the iso-truss structure  400 . The sign  406  may include various indicia.  
      Referring to  FIG. 60 , an iso-truss structure  410  may include a vertical component  412 , the horizontal component  414 , and a curved component  416  joining the vertical and horizontal components  412  and  414 . The vertical component  412  may be vertically oriented and secured to a support surface, such as a road side. The horizontal section  414  may be secured to the vertical section  412 , such as through a curved or acuate section  416 , as described above. A sign member  416  may be secured to the horizontal member  414 . Thus, a sign  416  may be suspended or elevated above a road way.  
      Referring to  FIG. 61 , an iso-truss structure  420  may include a pair of vertical members  422  and  424  disposed on opposite sides of a roadway. A horizontal component  426  may be suspended between the two vertical sections  422  and  424 . A sign member  428  may be secured to the horizontal member.  
      Utility Poles  
      Referring to  FIG. 62 , an iso-truss structure  440  may be vertically oriented and attached to a support surface, such as the ground. One or more arms  442  may be secured or attached to the iso-truss structure  440  at a location above the ground, and extend generally horizontally outwardly. Such arms  442  may be similar to the attachment member described above. Utilities lines  444 , such as phone, cable, or electrical lines, may be suspended from the arms  442 .  
      Referring to  FIG. 63 , the structural member  440  may include non-conductive attachment members  446  for attaching the utility lines  444  to the structure. The utility lines  444  may extend along a portion of the lengths of the iso-truss structure  440 .  
      Referring to  FIG. 64 , an iso-truss structure  450  may be vertically oriented and provided at its top end  452  with light structures or light sources  454  for providing illumination. Such light sources  454  may be secured to the top end  452 , such as with an end plate as described above.  
      Bicycle Frames  
      Referring to  FIGS. 65-74 , the iso-truss structures described above may be utilized for bike frames, and thus advantageously provide the advantages of strength and light weight. The bike frame includes a handle bar location  500  attached to a handle bar  502  and/or front fork  504 ; a seat location  506  for attachment to a seat stem  508 ; a pedal location  510  attached to a pedal assembly  512 ; a rear wheel location  514  attached to a rear wheel  516 . The frame  520  includes a plurality of members extending to and between the handle bar, seat, pedal and rear wheel locations  500 ,  506 ,  510 , and  514 . For example, the frame  520  includes a vertical member  522  extending between the pedal location  510  and the seat location  506 . In addition, the frame  520  includes a horizontal member  524  extending between the handle bar location  500  and the seat location  506 . Finally, the frame member  520  includes a diagonal member  526  extending between the handle bar location  500  and the pedal location  510 . The various components or sections  522 ,  524 , and  526 , are similar to the iso-truss structures described above, and are assembled to form a triangular frame  520 . The frame  520  provides strength and reduced weight.  
      Referring to  FIG. 66 , only a single diagonal member  532  extends from the handle bar location  500  to the vertical member  522 . The frame  530  forms something of a T-shape and eliminates a component for reducing weigh.  
      Referring to  FIG. 67 , another bike frame  540  may include an arcuate member  542  extending from the seat location  506  to the pedal location  510 , and a diagonal member  532  extending from the handle bar location  500  to the arcuate member  542 . The arcuate member  542  may more closely match the curvature of the rear wheel  516  and provide additional bending strength. Referring to  FIG. 68 , another bike frame  550  may include members  552  extending from the seat location  506  to the rear wheel location  514 , and another member  554  extending from the pedal location  510  to the rear wheel location  514 , or a triangle formed of the iso-truss structure. Thus, more of the frame may be formed of lighter weight iso-truss structure.  
      Referring to  FIG. 69 , another bike frame  560  may include a plurality of members which extend inwardly towards a central location  562 . A diagonal member  564  may extend from the handle bar location  500  to the cental location  562 . Similarly, a lower member  566  may extend from the pedal location to the central section  562 . Finally, an upper member  512  may extend from the seat location  560  to the central location  562 . Such a configuration utilizes straight structures which may be easier to manufacture.  
      Referring to  FIG. 70 , another bike frame  570  may utilize curved or arcuate members. For example, an upper member  572  may curve broadly from the handle bar location  500 , past the seat location  506 , and to the rear wheel location  514 . A lower member  574  may extend in a broad arc from the handle bar location  500  to the pedal location  510 . The curvature of the member  572  and  574  may provide additional strength. Referring to  FIG. 71 , another frame  580  may include a broad arcuate member  582  extending from the handle bar location  500  to the pedal location  510 , while an additional member  584  extends from the arcuate member  582  past the seat location  506  and towards the rear wheel location  514 .  
      Referring to  FIG. 72 , another bike frame  590  may include an upwardly curving member  592  extending from the handle bar location  500  pass the seat location to the rear wheel location  514 , while a lower member  594  extends from the handle bar location past the pedal location  510  and towards the rear wheel location  514 . Thus, the entire frame  590  is formed of the iso-truss structure.  
      Referring to  FIG. 73 , another bike frame  600  may have an S-shaped member  602  extending in a first arc from the handle bar location  500  and bending into a second arc extending towards the pedal location  510 . An upper member  604  extends from the seat location  506  in an arcuate fashion towards the S-shaped members  602 . Referring to  FIG. 74 , another bike frame  610  forms an S-shape member  612  extending from the handle bar location  500  to the pedal location  510 . A vertical member  614  extends upwardly from the pedal location  510  towards the seat location  506 . Finally, a rear member  616  extends from the vertical member  614  towards the rear wheel location  514 .  
      Referring to  FIGS. 75 and 76 , another bike frame  620  is shown in which iso-truss structures are disposed between connectors. A handle bar connector  622  may be disposed at the handle bar location  500  and configured to receive an upper horizontal member  624  and a lower diagonal member  626 . An upper horizontal member  624  and a lower diagonal member  626  may be received on extensions of the handle bar connector  622 . A seat connector  628  may be disposed at the seat location  506  and have extensions to receive the upper horizontal member  624  and a vertical member  630 . A lower member  632  is attached at the pedal location  510  and has extensions to receive the lower diagonal member  626  and the vertical member  630 . Thus, relatively straight iso-truss structures  624 ,  626 , and  630  may be utilized and attached to the connectors  622 ,  628 , and  632 .  
      Method of Manufacturing  
      As discussed above, the iso-truss structures preferably are formed by fibers impregnated with resin. In addition, the iso-truss structures or helical components preferably are formed by continuous strands of fiber wrapping around the longitudinal axis and along the length of the iso-truss structure. Such a composite iso-truss structure may be formed using a mandrel. It will be appreciated that the complicated geometry of the iso-truss structure presents a manufacturing challenge.  
      Referring to  FIG. 77 , a mandrel  700  is shown with fibers  702  disposed thereon forming the iso-truss structures described above. The mandrel  700  can be elongated and shaped to match the desired shape of the iso-truss structure. For example, as shown in  FIG. 77 , the mandrel  700  is elongated and straight to form an elongated and straight iso-truss structure. It is, of course, understood, that the mandrel  700  may be curved or arcuate, or form other angles in accordance with the desired shape of the iso-truss structure. In addition, the mandrel  700  can be rotationally disposed such that the mandrel  700  may be rotated as the fibers  702  are wrapped thereon.  
      The mandrel  700  may include an elongated core or body  704 , and a plurality of heads  706  disposed thereon. The core or body  704  preferably has a reduced or smaller diameter with respect to the iso-truss structure, such that the core or body  704  may reside within the iso-truss structure without interfering with any of the segments or helical components. The heads  706  preferably are spaced apart from the core or body  704 . The heads  706  extend radially from the core or body  704  and towards the exterior nodes  122  of the iso-truss structure. The heads  706  are configured to receive the strands of fiber  702  as they are wrapped about the mandrel  700 . Therefore, for an eight node iso-truss structure, eight heads  706  extend radially around the circumference of the core or body  704 . In addition, a number of heads  706  extend along the length of the core or body  704  in accordance with the length of the desired iso-truss structure.  
      Referring to  FIG. 78 , the heads  706  are shown in greater detail. Each head  706  preferably includes a plurality of indentations  710  for receiving strands of fibers  702 . The indentations  710  preferably include two sets of deep indentations  712  and  714  for receiving the strands of fiber  702  forming a pair of opposing helical components. Thus, the set of deep indentations  712  and  714  preferably extend downwardly at an angle to match the angle of the segments. Each set of deep indentations  712  and  714  preferably include two aligned indentations formed at an angle with respect to one another such that each indentation of the set is performing a different segment of the same helical component. The inner section of the indentations  716  is located at the exterior node  122  of the iso-truss structure.  
      In addition, the indentations  710  preferably include one or more sets of shallow indentations  718  and  720 . One set of shallow indentations  718  may be utilized to form longitudinal components of the iso-truss structure, while the other shallow indentations  720  may be utilized to form radial or lateral components of the iso-truss structure.  
      In order to form an iso-truss structure as described above, strands of fiber can be wrapped around the mandrel in order to create the helical components and segments thereof. The strands of fiber  702  may be wrapped about the mandrel as described above with respect to the helical components, placing the strands of fiber in the indentations of the head. In addition, the strands of fiber may be impregnated with resin as they are wrapped around the mandrel  700 . Alternatively, the strands of fiber may be wrapped around the mandrel without impregnating them with resin as discussed above to form a braided pre-form. The resin is then cured and the mandrel may then be removed from the iso-truss structure. Alternatively, the iso-truss structure may be integrally formed with a mandrel and the mandrel may remain therein.  
      It will be appreciated that the complex geometry of the iso-truss structure, and the extension of the heads from the mandrel, create a challenge in removing the mandrel from the iso-truss structure. Various types of mandrels may be utilized in order to form the iso-truss structure. For example, a dissolvable mandrel may be formed by salt, or sand with a binder, which is dissolved to remove the mandrel from the iso-truss structure. As another example, eutectic metals may be used which can be melted away from the iso-truss structure. As another example, a balloon mandrel may be utilized which includes a sand-filled bladder which is packed with sand and vacuum sealed to form the mandrel, and then the vacuum is released and the bladder emptied of sand to remove the mandrel from the iso-truss structure.  
      In addition, the iso-truss structure may be formed by wet or dry wrapping fibers around an internal mold, and then enclosed by an external mold, similar to injection molding. Such a molding process can provide good consolidation, good shape definition, and good surface finish.  
      Referring to  FIG. 79 , a collapsible mandrel  720  is shown which advantageously may be removed from an iso-truss structure and reused. The collapsible mandrel  720  is similar to the mandrel  700  described above and can include an elongated tubular body  722  and a plurality of beads  724 . The hollow tubular body  722  can include a plurality of holes or apertures  726  for receiving a plurality of pins  728  therein. The pins  728  may be inserted through the holes or apertures  726  of the tubular body  722 , and the heads  724  disposed on a pin  728 . Thus, the heads  724  extend from the tubular body  722  on the pin  728 . An elongated core  730  is removably disposed within the tubular body  722 . In addition, a plurality of inserts  732  are also removably disposed in a tubular body  722  between the core  730  and the tubular body  722 . The insert  732  also includes a plurality of holes or apertures  734  for receiving the pin  728 . Thus, the pin  728  extends through the tubular body  722  and the insert  734  to abut the core  730 . Thus, the core  730  maintains the heads extending from the tubular body  722  on the pin  728 .  
      After the iso-truss structure has been formed on the mandrel  720 , the core  730  may be removed from the tubular body  722  by sliding the core  730  outwardly from the tubular body  722 . Removal of the core  730  allows the insert  732  to be removed from the tubular body  722 , and the pins  728  to move inwardly into the tubular body  722 . Thus, the pins may be removed and the tubular body  722  removed from the iso-truss structure. In addition, the heads  724  may be removed.  
      Referring again to  FIG. 77 , an end plate  120  may be disposed on the mandrel  700  at one or both ends thereof. As discussed above with respect to the  FIGS. 12   a  and  b , the end plate  120  has a hole or aperture  124  through which the core or body  704  of the mandrel  700  may be received. The strands of fiber  702  may then be wrapped around the indentations  123  through the end plate  120  to integrally form the end plate  120  with the iso-truss structure. The core or body  704  of the mandrel  700  may then be removed through the aperture  124  of the end plate  120 .  
      The mandrel  740  may be assembled by inserting the pins  728  into apertures in the core or tube  722 . Collars also may be disposed at the ends of the tube  722  to form the integral connectors, as described above. The heads  724  are disposed on the pins  728 . The fibers are wrapped about the heads  724  to form the helical members and axial members. In addition, the fibers are wrapped around the collars to form the integral connectors. The mandrel is removed to leave the structure.  
      Additional Applications  
      Referring to  FIG. 80 , a support member  750  may utilize an elongated iso-truss structure  752  as discussed above to hold and secure precast concrete forms  754 . The support member  750  may include an iso-truss structure  752  with end plates  120  on the ends thereof to receive connection members  754  and  756  for engaging the ground and the concrete form  754 . The strength of the iso-truss structure  752  provides strength for holding up the precast concrete form  754 , while the light weight of the iso-truss structure  752  allows the support members  750  to be easily manipulated and handled.  
      Referring to  FIG. 81 , basketball support  760  is shown for supporting a basketball standard  762 . The basketball support  760  may include an iso-truss structure  764  as described above. The basketball support  760  may include a vertical iso-truss section  766  and a horizontal iso-truss structure  768  connected to the vertical section  766  for extending the basketball standard  762  over the court.  
      Referring to  FIG. 82 , a backpack  770  may include a frame  772  which utilizes iso-truss structure  774  as described above. The frame  772  may include a perimeter formed of iso-truss structures including a pair of spaced apart vertical members and interconnecting horizontal members. The iso-truss structure  774  provides strength and light weight to the backpack  770 . Referring to  FIG. 83 , iso-truss structure  790  may be utilized to form a mast or other support structures  792  on a boat  794  or other marine structure. The iso-truss structure  790  may be formed with composite material, and thus resist corrosion.  
      Referring to  FIG. 84 , a bridge  800  is shown utilizing an iso-truss structure  802 . The iso-truss structure  802  may be arcuate and various bridge components may be suspended therefrom.  
      Referring to  FIGS. 85 and 86 , an oil platform  810  is shown utilizing iso-truss structures  812  as support columns for supporting the oil platform  810 . Again, these iso-truss structures  812  preferably are formed with composite material to resist corrosion. In addition, the open structure of the iso-truss structures  812  provide lower drag forces on a structure.  
      Referring to  FIG. 87 , an iso-truss structure  830  is shown utilized with a submarine  832 . The iso-truss structure  830  provides the internal structure supporting the hull  834  of the submarine  832 . Thus, the hull  834  is formed around the iso-truss structure  830 , while the interior of the iso-truss structure  830  may be utilized for the crew, and interior wall support. In addition, the hollow or open structure between the segments or helical components of the iso-truss structure  830  may also be utilized for equipment, piping, etc. It is, of course, understood that the iso-truss structures may be utilized for other structures, vehicles, and vessels.  
      Referring to  FIG. 88 , an iso-truss structure  840  may be utilized for aircraft or airborne devices such as artillery or missiles  842 . Again, the iso-truss structure  840  provides an exterior shell or exoskeleton for supporting an outer skin, and an interior for containing other items. Thus, the iso-truss structure  840  provides strength and light weight, which is particularly useful in aircraft or airborne applications. Referring to  FIGS. 89   a  and  b , an iso-truss structure  842  may be included as part of the fuselage of an aircraft. Passenger seats may be located in the central void or space of the structure  842 , while other components, such as wiring, hydraulics, fuel lines, etc., may be disposed within the structure  842  itself, or between the segments. Such iso-truss structures also may be utilized for wing structures, and other components of the aircraft.  
      Referring to  FIG. 90 , the structures described above also may be utilized in aerospace applications, such as with satellites or other orbiting structures  844 . The structures may be collapsible/expandable to optimize limited cargo space. The structures also may be partially formed, such as a braided preform described above, and finally formed in space.  
      Referring to  FIG. 91 , iso-truss structures  846  also may be utilized in water tower applications.  
      The iso-truss structures can be used in buildings and construction. Referring to  FIG. 92 , a roofing system  900  can utilize iso-truss structures similar to those described above. Inclined or horizontal iso-truss structures  902  can form beams to support a roof  904 . Vertical iso-truss structures  906  can be used as columns to support the roof inclined iso-truss structures  902 . The iso-truss provides structural strength, and is light weight.  
      The iso-truss structures can be used in vessels, boats and ships. Referring to  FIG. 93 , a kayak  910  can utilize tapping iso-truss structures as described above. A frame  912  can be formed by an iso-truss structure that tappers at each end. A skin or shell  914  can be formed over the frame  912 . A portion or side  916  of a bay of the iso-truss can be removed to allow access into the kayak  910 , and allow the user&#39;s body to extend through the frame  912 , and into the hollow of the frame. The iso-truss provides structural strength to the kayak, while providing space on the interior for the passenger.  
      Referring to  FIG. 94 , a solid fuel rocket  917  is shown with an iso-truss structure  918 . The solid rocket fuel can be disposed about the members of the iso-truss. The iso-truss can burn as the rocket fuel burns, thus eliminating falling rocket casings. The nozzle  919  can be configured to travel along the rocket  917  as the fuel and iso-truss burn.  
      Referring to  FIG. 95 , an artificial reef  920  can be created using a plurality of iso-truss structures  922 . The iso-truss can be weighted so that it sinks to the bottom of the sea floor. For example, a weight  924 , such as concrete, can be attached to one end of the iso-truss. The other end can be free to extend upwardly from the sea floor. Thus, the iso-truss can be transported to the desired location, and dropped overboard. Several iso-truss structures can be attached together. The iso-truss structures can be formed with an environmentally friendly epoxy to promote growth on the iso-truss.  
      The iso-truss structures also can be used to transmit torque or rotational movement. Referring to  FIG. 96 , a drive shaft  930  can be formed with an iso-truss structure  932  similar to those described above. The drive shaft or iso-truss can be rigid or flexible. One end of the drive shaft  930  can be coupled to an engine or transmission  934 , while the other end can be coupled to a transfer case or wheel  936 . Such a configuration can be useful for vehicles. It will be appreciated that such a drive shaft can be used in other applications as well. In addition, the iso-truss can be used for drills, such as oil, water and mining drills. In such a configuration, one end can be coupled to a driver, while the other end is coupled to a drill bit or cutter.  
      Referring to  FIG. 97 , a shock absorber  940  utilizes an iso-truss structure  942  with no axial members. Thus, the iso-truss structure can compress in a longitudinal or axial direction to absorb shock. In addition, a bladder  944 , such as a gas filled bladder, can be disposed in the iso-truss.  
      Referring to  FIG. 98 , an iso-truss structure  950  can be configured with both rigid sections  952 , and a flexible section  954  to form a joint. The rigid sections  952  can be formed with axial members for stiffness or rigidity, while the flexible section  954  can be formed without the axial members for flexibility.  
      Referring to  FIG. 99 , a tank or pressure vessel  960  can include an iso-truss structure  962  in which an continuous interior wall  964  is formed. The tank or pressure vessel  960  can contain fluids, such as liquids or gases.  
      Referring to  FIG. 100 , a gear system  970  includes a plurality of gears  972  formed of iso-truss structures which rotate and engage one another. The exterior nodes of the gears  972  or iso-truss structures intermesh.  
      Referring to  FIGS. 101   a  and  101   b , impact barriers  974  and  976  can include iso-truss structures. The iso-truss structure can be oriented to be impacted axially or longitudinally, as shown in  FIG. 101   a , or laterally, as shown in  FIG. 101   b . Referring to  FIGS. 102   a  and  102   b , the impact barriers can include a compressible material, such as foam, disposed in and/or around the iso-truss structure. In one aspect, the foam material  980  can form a shell around all or some of the iso-truss structure, and between the internal and external nodes. In another aspect, the foam material  982  can be disposed in the interior of the iso-truss structure.  
      Referring to  FIGS. 103   a - c , the iso-truss structure can be elongated on one side, or in one direction, to create an elongated cross-section. Such configuration can be better suited or more efficient in applications where one direction has preferential loading, such as a floor joist. The configuration can have different structural properties in different directions, so that the iso-truss can be configured for the loads of a particular application.  
      The configurations shown in  FIGS. 103   a - c  are similar in many respects to the iso-truss structures described above and illustrated herein. Some of the segments of the helical components have been elongated with respect to the others, or have a greater length, to create the elongated cross section. In addition, the angular orientation between some adjacent or sequential segments is greater.  
      Referring to  FIG. 103   a , an eight node iso-truss structure  1000  is shown. Some of the helical components include longer segments  1002  and shorter segments  1004  to create a rectangular cross sectional shape. For example, the helical and reverse helical components can form the rectangular cross sectional shape. Other of the helical components include larger angles  1006  between some adjacent segments, and smaller angles  1008  between other adjacent segments, to create a diamond shaped cross section. For example, the rotated and rotated reverse helical components can form the diamond shaped cross section.  
      Referring to  FIG. 103   b , a ten node iso-truss structure  1010  is shown which is elongated to have a more elliptical shape. The helical components can have both 1) segments of different lengths, and 2) different angles between adjacent segments. For example, the helical and reverse helical components can form a first, elongated pentagon  1012 , while the rotated and rotated reverse helical components form a second, elongated pentagon  1014 , which together form the elliptical shape. In addition, the helical components have five segments forming a single, substantially complete rotation.  
      Referring to  FIG. 103   c , another iso-truss structure  1020  is shown which has multiple cross sectional shapes. The structure  1020  can include both rectangular cross sectional shapes, and elongated diamond cross sectional shapes. The helical components have four segments per rotation, but utilizes three helical components for every two helical components in the typical structure.  
      The iso-truss structures described above can be utilized in other applications as well. For example, the iso-truss structure can be included in the mast of a boat with a sail coupled thereto. The iso-truss structure can be included in a flag post with a flag coupled thereto. The iso-truss structure can be included in a fence post with fence members attached thereto.  
      In addition, a skin, covering or wrap may be disposed around the structure. Such a skin may strengthen the structure, prevent climbing, and/or be aesthetic.  
      The iso-truss structures described above also may be utilized to reinforce concrete. For example, concrete may be poured or otherwise formed about the structures, and may fill the interior of the structures.  
      The iso-truss structures have been described above with particular reference to an eight node structure in which the helical components have four straight segments forming a single, complete rotation about the axis. It is of course understood that other configuration can be useful, including for example, structure with five, six, seven, nine, twelve, etc. nodes.  
      It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements. Thus, while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made, without departing from the principles and concepts of the invention as set forth in the claims.