Patent Publication Number: US-11028573-B1

Title: Serrated beam

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/962,008, filed Jan. 16, 2020, the entire disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a structural beam section primarily intended to transfer vertical loads through shear and flexural actions along the length of the member to one or more structural supports. 
     Description of Related Art 
     Composite beams and joists are widely used in conventional steel construction. Typically, the beam or joist is located entirely below the composite slab-on-deck assembly. The transfer of horizontal shear forces between the concrete slab and the steel beam or joist is most commonly accomplished through the use of shear connectors, often in the form of headed anchor studs, which are welded to the top of the beam or joist prior to slab placement. 
     SUMMARY OF THE INVENTION 
     The present invention utilizes a serrated top flange encased in the concrete slab wherein the headed serrations provide for the transfer of horizontal shear forces between the steel member and the concrete slab. The present invention utilizes a serrated top flange encased in the concrete slab wherein the serrations provide for the transfer of horizontal shear forces between the steel member and the concrete slab. The present invention is directed toward a structural member assembly spanning substantially horizontally between one or more supports wherein the top flange of the cross section is comprised of serrated geometry. In one embodiment, the serrated geometry comprises portions of one or both sides of the top flange of an I-beam being cut out in an alternating pattern. Many cut-out patterns in the flange, as well as configurations of steel member shapes and flange orientations are possible. The top flange of the cross section is intended to be encased by a typically concrete slab such that the serrations in the top flange of the member are encapsulated or encased by the concrete slab and, thereby facilitate horizontal shear transfer between the cross section and the surrounding slab medium thereby creating composite action between the member and surrounding slab. The primary function of this composite beam member is to transfer vertical loads applied along the length of the beam member to one or more supports along the length of the member through shear and flexural forces in the composite assembly. 
     The member may be comprised of unitary construction or built-up of structural plates, angles, ‘T’ shaped, ‘I’ shaped, rectangular or other similar geometric cross sections, though the use of other cross sections are also within the scope of the present invention. The serrations each side of the top flange of the member may be aligned in various configurations, such as alternating portions on the respective sides of the web, or mirror images on either side of the web. Multiple shapes of cut-outs and remaining portions of the flange are provided but may take the form of any shape which facilitates the composite action contemplated herein. 
     In one embodiment, the member may be self-contained as a beam acting compositely with the surrounding slab. The serrations are comprised of headed geometry whereby the head at the end of each serration has a width measured parallel to the long direction of the member greater than that of the serration shaft, which is disposed between the serration head and the member top flange. While the shape of the head and shaft of the serrations in this embodiment is substantially rectangular, the use of square, circular, elliptical, bulbed, ‘L’ shaped, ‘T’ shaped or other geometry for each of the head and shaft, or for head and shaft as a unit, is within the scope of the present invention. 
     In a second embodiment, additional structural elements may be attached to the top or bottom of the member such that the member acts as the top or bottom chord of a joist or truss assembly, or as the top or bottom flange section of a deep built-up girder. The serrations each side of the top flange of the member may be aligned or staggered. While the shape of the serrations may be substantially rectangular, the use of square, circular, elliptical, bulbed, shaped, ‘T’ shaped or other geometry is also within the scope of the present invention. 
     While the member is envisioned to be comprised of steel material and the slab comprised of concrete material, the use of other materials is also within the scope of the present invention. The member in its entirety or individual components of the member may be formed from metal, primarily structural steel, through known fabrication processes such as cutting from plate, casting, built up of welded or bolted shapes, machining, forming from cold bending of plates, extruding, hot rolling, or from other fabrication or manufacturing processes. However, other known materials, such as carbon fiber or other metals, and other manufacturing processes are also within the scope of the present invention. 
    
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings form a part of the specification and are to be read in conjunction therewith, in which like reference numerals are employed to indicate like or similar parts in various views. 
         FIG. 1  is a schematic side view of one embodiment of a load carrying member spanning to three structural supports in accordance with the teachings of the present disclosure; 
         FIG. 2A  is a cross sectional view of one embodiment of a member and slab assembly in accordance with the teachings of the present disclosure; 
         FIG. 2B  is a top view of one embodiment of a serrated top flange in accordance with the teachings of the present disclosure and which may be used in the member of  FIG. 2A ; 
         FIG. 3A  is a cross sectional view of one embodiment of a member and slab assembly in accordance with the teachings of the present disclosure; and 
         FIG. 3B  is a top view of one embodiment of a serrated top flange in accordance with the teachings of the present disclosure and which is included in the member of  FIG. 3A . 
         FIG. 4A  is a cross sectional view of one embodiment of a member and slab assembly wherein the bottom chord of the truss, or bottom flange of the built-up member is comprised of two ‘L’ shaped sections in accordance with the teachings of the present disclosure; and 
         FIG. 4B  is a top view of one embodiment of a serrated top flange in accordance with the present disclosure and which may be included in the members of  FIG. 4A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description of the present invention references the accompanying drawing figures that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the present invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the spirit of the scope of the present invention. The present invention is defined by the appended claims and, therefore, the description is not to be taken in a limiting sense and shall not limit the scope of the equivalents to which such claims are entitled. 
       FIG. 1  shows a schematic view of a member  1 , or member and slab assembly acting compositely  1 , spanning between three structural supports  2 . The member  1 , or member and slab assembly acting compositely  1 , is capable of transferring vertical loads applied along the length of the member to the structural supports  2  through shear and flexural forces in the member  1 , or member and slab assembly acting compositely  1 . 
       FIGS. 2A and 2B  show an embodiment of a member and slab assembly  10  in which the serrated top flange of the member  20   a  is interconnected to the vertical web of the member  32   a . The vertical web of the member  32   a  is interconnected to the bottom flange of the member  31   a . The serrated top flange of the member  20   a  and vertical web of the member  32   a  are encased by the concrete slab  43   a . As best seen in  FIG. 2B , the headed serrations  21   a  on one side of serrated top flange  20   a  are staggered along the length of serrated top flange  20   a  in relation to the serrations  21   a  on the opposite side of serrated top flange  20   a . Each serration  21   a  is comprised of a head  23   a  and a shaft  22   a  whereby the width “WH” of the head  23   a  measured parallel to the long axis of the top flange  20   a  is greater than the width “WS” of the shaft  22   a  measured parallel to the long axis of the top flange  20   a . The headed serrations  21   a  engage the concrete slab  43   a  such that the serrated top flange  20   a  and the concrete slab  43   a  undergo strains of similar magnitude and direction under applied loading along the length of top flange  20   a  thereby creating composite action. Decking  41   a  spans between the bottom flange of the member  31   a  to support concrete slab  43   a  during placement and participates in transferring superimposed loads imparted to the concrete slab  43   a  to the bottom flange of the member  31   a . Intermittent struts  42   a  brace the serrated top flange of the member  20   a  to the decking  41   a  to resist horizontal movement perpendicular to the long direction of the serrated top flange  20   a  thereby mitigating lateral torsional buckling of the member during placement of the concrete slab  43   a.    
     Generally throughout, concrete slab  43   a  the use of concrete may be another structural medium which can be poured or installed in more of a liquid state, then cured or solidified into a more rigid or solid state. Concrete is a good example, but it could be flowable grout, epoxy mixtures, or other similar structural medium. 
       FIGS. 3A and 3B  show an embodiment of a member and slab assembly  11  in which the serrated top flange of the member  20   b  is interconnected to two vertical webs of the member  32   b . Each vertical web of the member  32   b  is interconnected to a bottom flange of the member  31   b  such that each web and bottom flange assembly together comprise an ‘L’ shape. The serrated top flange of the member  20   b  and vertical webs of the member  32   b  are encased by the concrete slab  43   b . The headed serrations  21   b  on one side of the serrated top flange  20   b  are substantially aligned with the serrations  21   b  on the opposite side of serrated top flange  20   b . Each serration  21   b  is comprised of a head  23   b  and a shaft  22   b  whereby the width of the head  23   b  measured parallel to the long axis of the top flange  20   b  is greater than the width of the shaft  22   b  measured parallel to the long axis of the top flange  20   b . As further shown in  FIG. 3B , in one embodiment, head  23   b  of serration  21   b  may include sides  24  that are substantially linear, and shaft  22   b  of serration  21   b  may also include sides  25  that are substantially linear. As further shown in  FIG. 3B , the plurality of serrations  21   b  define a plurality of voids  26  wherein it is shown that the shape of the void defined by the serrations  21   b  is a substantial mirror image of the shape of the serrations  21   b . The headed serrations  21   b  engage the concrete slab  43   b  such that the serrated top flange  20   b  and the concrete slab  43   b  undergo strains of similar magnitude and direction under applied loading along the length of top flange  20   b  thereby creating composite action. Decking  41   b  spans between the bottom flanges of the member  31   b  to support concrete slab  43   b  during placement and participates in transferring superimposed loads imparted to the concrete slab  43   b  to the bottom flanges of the member  31   b . Intermittent struts  42   b  brace the serrated top flange of the member  20   b  to the decking  41   b  to resist horizontal movement perpendicular to the long direction of the serrated top flange  20   b  thereby mitigating lateral torsional buckling of the member during placement of the concrete slab  43   b.    
       FIG. 4A  shows an embodiment of a truss, joist or built-up girder assembly  50  in which the top chord of the truss or joist, or top flange of the built-up girder, is comprised a member and slab assembly  12 . Member slab assembly  12  is interconnected to truss or joist web members  60  in the case of a truss or joist assembly  50 , or a web plate  60  in the case of a built-up girder assembly  50 . In one embodiment, a serrated flange  20   c  is connected to web  32   c , which may be a WT section or a built-up member. Similar to other embodiments, decking  41   c  may be supported by a flange member  52  that can either carry compression or tension bending force depending upon where the neutral axis of the composite shape is located. In most embodiments, flange member  52  will typically carry compression force and decking  41   c  laterally braces flange  52  to prevent buckling. In addition, intermittent struts  42   c  may also be utilized in the member slab assembly. In some embodiments, the intermittent struts not only provide stability when pouring the concrete, but also are encased by the slab and may contribute to the composite performance of the member slab assembly  12 . 
     As further shown in  FIG. 4A , the bottom chord of the truss or joist assembly  50 , or bottom flange of a built-up girder assembly  50 , is comprised two ‘L’ shaped sections  70 . The ‘L’ shaped sections  70  are interconnected to the truss or joist web members  60  in the case of a truss or joist assembly  50 , or a web plate  60  in the case of a built-up girder assembly  50 . In one embodiment, the web plate  60  of a built-up girder may have a series of openings, such as a castellated beam.  FIG. 4B  shows an embodiment of member and slab assembly  12  in which the serrated top flange of the member  20   c  is interconnected to the vertical web of the member  32   c . The vertical web of the member  32   c  is interconnected to a bottom flange of the member  52 . The serrated top flange of the member  20   c  and vertical webs of the member  32   c  are encased by the concrete slab  43   c . The serrations  21   c  on one side of the serrated top flange  20   c  are staggered along the length of serrated top flange  20   c . The substantially rectangular serrations  21   c  engage the concrete slab  43   c  such that the serrated top flange  20   c  and the concrete slab  43   c  undergo strains of similar magnitude and direction under applied loading along the length of top flange  20   c  thereby creating composite action. In this embodiment, the substantially rectangular serrations  21   c  include a shaft  22   c  and a head  23   c  having the same width to define the substantially rectangular shape. Decking  41   c  spans between the bottom flanges of the member  31   c  to support concrete slab  43   c  during placement and participates in transferring superimposed loads imparted to the concrete slab  43   c  to the bottom flanges of the member  52 . Intermittent struts  42   c  brace the serrated top flange of the member  20   c  to the decking  41   c  to resist horizontal movement perpendicular to the long direction of the serrated top flange  20   c  thereby mitigating lateral torsional buckling of the member during placement of the concrete slab  43   c.    
     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. 
     The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. 
     As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.