Abstract:
A test fixture for applying a prescribed displacement to a material includes a first and a second portion, a first and second adjustable pin, and an actuator. The first portion includes a first pin that engages the material at a first location on the material. A second pin engages the material at a second location on the material. A third pin engages the material at a third location on the material. The first adjustable pin holds the material against the second pin at the second location. The second adjustable pin holds the material against the third pin at the third location. The actuator is adapted to configure a relative position between the first pin and the second and third pins.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/531,340, filed Sep. 6, 2011, which application is hereby incorporated by reference in its entirety. 
     
    
     FIELD 
       [0002]    The inventive aspects of this disclosure pertain to devices and methods for testing materials. 
       BACKGROUND 
       [0003]    Material tests and standards have been devised to qualify materials for use in particular applications. These tests include strength tests, deflections tests, chemical resistance tests, fatigue tests, etc. Certain of these tests may test combinations of properties and/or subject a test specimen to several test conditions simultaneously (e.g., a deflection test combined with a chemical resistance test). There is a need for test fixtures to efficiently perform tests on a range of materials. 
       SUMMARY 
       [0004]    An aspect of the present disclosure relates to a test fixture for applying a prescribed displacement to a material. The test fixture includes a first portion, a second portion, and an actuator. The first portion includes a first material engaging feature and a first support. The first material engaging feature includes a supported end mounted to the first support and a free end spaced from the supported end of the first material engaging feature. The first material engaging feature is adapted to engage the material between the supported end and the free end of the first material engaging feature at a first location on the material. The second portion includes a second material engaging feature, a third material engaging feature, and a second support. The second and the third material engaging features each have a supported end mounted to the second support. The second and the third material engaging features are spaced from each other by a distance. The second and the third material engaging features each include a free end spaced from the supported ends of the second and the third material engaging features. The second material engaging feature is adapted to engage the material between the supported end and the free end of the second material engaging feature at a second location on the material. The third material engaging feature is adapted to engage the material between the supported end and the free end of the third material engaging feature at a third location on the material. The actuator is operably connected between the first support of the first portion and the second support of the second portion. The actuator is adapted to configure a relative position between the first material engaging feature and the second and third material engaging features. 
         [0005]    Another aspect of the present disclosure relates to a test fixture for simultaneously applying prescribed displacements to a plurality of test specimens. The test fixture includes a first portion, a second portion, and an actuator. The first portion includes a plurality of material engaging features. The material engaging features of the first portion are each adapted to engage one of the test specimens at a first location on the test specimen. The second portion includes a plurality of pairs of material engaging features. The pairs of material engaging features of the second portion are each adapted to engage one of the test specimens at a second location and a third location on the test specimen. One of the pair of material engaging features is adapted to engage the test specimens at the second locations, and another of the pair of material engaging features is adapted to engage the test specimens at the third locations. The actuator is operably connected between the first portion and the second portion. The actuator is adapted to configure a relative position between the material engaging features of the first portion and the pairs of material engaging features of the second portion. 
         [0006]    Still another aspect of the present disclosure relates to a test fixture for applying a prescribed displacement to a material. The test fixture includes a first portion, a second portion, a first adjustable material support feature, a second adjustable material support feature, and an actuator. The first portion includes a first pin. The first pin is adapted to engage the material at a first location on the material. The second portion includes a second pin and a third pin. The second and the third pins are spaced from each other by a distance. The second pin is adapted to engage the material at a second location on the material. The third pin is adapted to engage the material at a third location on the material. The first adjustable material support feature is adapted to hold the material against the second pin at the second location on the material. The second adjustable material support feature is adapted to hold the material against the third pin at the third location on the material. The actuator is operably connected between the first portion and the second portion. The actuator is adapted to configure a relative position between the first pin and the second and third pins. 
         [0007]    A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a test fixture in accordance with the principles of the present disclosure; 
           [0009]      FIG. 2  is an exploded perspective view of the test fixture of  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view of a base of the test fixture of  FIG. 1 ; 
           [0011]      FIG. 4  is an end elevation view of the base of  FIG. 3 ; 
           [0012]      FIG. 5  is a bottom plan view of the base of  FIG. 3 ; 
           [0013]      FIG. 6  is a perspective view of a stationary material engaging portion of the test fixture of  FIG. 1  including a plate and a plurality of material engaging pins; 
           [0014]      FIG. 7  is a top plan view of the plate of the stationary material engaging portion of  FIG. 6 ; 
           [0015]      FIG. 8  is an elevation view of the material engaging pin of the stationary material engaging portion of  FIG. 6 ; 
           [0016]      FIG. 9  is a perspective view of a moveable material engaging portion of the test fixture of  FIG. 1 ; 
           [0017]      FIG. 10  is an end elevation view of an end-piece of the test fixture of  FIG. 1 ; 
           [0018]      FIG. 11  is a top plan view of the end piece of  FIG. 10 ; 
           [0019]      FIG. 12  is an opposite end elevation view of the end piece of  FIG. 10 ; 
           [0020]      FIG. 13  is a bottom plan view of the end piece of  FIG. 10 ; 
           [0021]      FIG. 14  is a side elevation view of the end piece of  FIG. 10 ; 
           [0022]      FIG. 15  is a side elevation view of an actuating screw of the test fixture of  FIG. 1 ; 
           [0023]      FIG. 16  is a perspective view of a compression washer of the test fixture of  FIG. 1 ; 
           [0024]      FIG. 17  is an end elevation view of a retaining member of the test fixture of  FIG. 1 ; 
           [0025]      FIG. 18  is an exploded perspective view of a support pin assembly of the test fixture of  FIG. 1 ; 
           [0026]      FIG. 19  is a cross-sectional side elevation view of a pin of the support pin assembly of  FIG. 18 ; 
           [0027]      FIG. 20  is a side elevation view of a plunger of the support pin assembly of  FIG. 18 ; 
           [0028]      FIG. 21  is a top plan view of the test fixture of  FIG. 1  in an un-actuated configuration; 
           [0029]      FIG. 22  is a top plan view of the test fixture of  FIG. 1  in a partially actuated configuration; 
           [0030]      FIG. 23  is a top plan view of the test fixture of  FIG. 1  in a fully actuated configuration; 
           [0031]      FIG. 24  is a side elevation view of the test fixture of  FIG. 1  in the fully actuated configuration of  FIG. 23 ; 
           [0032]      FIG. 25  is an end elevation view of the test fixture of  FIG. 1 ; 
           [0033]      FIG. 26  is a top plan view of the test fixture of  FIG. 1  in the fully actuated configuration of  FIG. 23  with a first test specimen loaded therein; 
           [0034]      FIG. 27  is a top plan view of the test fixture of  FIG. 1  in the fully actuated configuration of  FIG. 23  with a second test specimen loaded therein; and 
           [0035]      FIG. 28  is a top plan view of the test fixture of  FIG. 1  in the fully actuated configuration of  FIG. 23  with a set of the first test specimens of  FIG. 26  loaded therein. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    Reference will now be made in detail to the exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like structure. 
         [0037]    The present disclosure concerns test fixtures for qualifying material for a given application and/or determining whether a material sample meets a given specification. In particular, an example test fixture  30  is disclosed that tests various materials under various bending conditions. The various materials can vary in thickness, stiffness (e.g., modulus of elasticity), strength, creep, chemical resistance, etc. The example test fixture  30  can impose various deformation profiles on the various material samples (e.g., test specimens). In the depicted use of the test fixture  30 , as illustrated at  FIGS. 26-28 , the test fixture  30  constrains material samples  800  or  900  at two locations L 1   1,2  and L 2   1,2 , respectively, that are spaced apart from each other by, or approximately by, a predetermined distance D S . The test fixture  30  can displace the material samples  800 ,  900  at a third location L 3   1,2 , between the two constrained locations L 1   1,2 , L 2   1,2 , by a predetermined distance D 1,2 . As depicted, the material samples  800 ,  900  are initially straight and are deformed to deformation profiles P 1,2  by the test fixture  30 . 
         [0038]    Referring now to  FIGS. 1 and 2 , the test fixture  30  will be described in detail. The test fixture  30  extends between a first end  32  and a second end  34 . The test fixture  30  also includes a first side  36 , a second side  38 , a top  40 , and a bottom  42 . The test fixture  30  can be configured in multiple configurations.  FIG. 21  illustrates a first configuration  44  of the test fixture  30 .  FIG. 23  illustrates a second configuration  48  of the test fixture  30 . As depicted, the first configuration  44  and the second configuration  48  position the test fixture  30  at opposite ends of a range of available configurations.  FIG. 22  illustrates an intermediate configuration  46  between the first configuration  44  and the second configuration  48 . The test fixture  30  is configurable to other intermediate configurations between the first configuration  44  and the second configuration  48 . An intermediate configuration (e.g., the intermediate configuration  46 ) can be chosen to meet the requirements of a material test performed by the test fixture  30 . The first configuration  44  or the second configuration  48  can also be chosen to meet the requirements of a material test performed by the test fixture  30 . 
         [0039]    The test fixture  30  includes a base  100 , a stationary portion  200 , a moveable portion  300 , an adjustment bracket  400 , an actuator  500 , a preloading member  540 , a keeper  560 , a plurality of support pin assemblies  600 , and a plurality of stacking pins  704 . As depicted, a material sample or material samples are held between the stationary portion  200  and the moveable portion  300 . The actuator  500  moves the moveable portion  300  relative to the stationary portion  200 . By moving the moveable portion  300  relative to the stationary portion  200 , the material sample or the material samples are deformed (e.g., according to a predetermined requirement and/or to a predetermined deformation profile). 
         [0040]    Turning now to  FIGS. 3-5 , the base  100  will be described in detail. The base  100  extends between a first end  102  and a second end  104 . As depicted, the second end  104  of the base  100  generally corresponds to the second end  34  of the test fixture  30 . The base  100  further includes a first side  106 , a second side  108 , a top  110 , and a bottom  112 . As depicted, the first side  106  of the base  100  generally corresponds to the first side  36  of the test fixture  30 , the second side  108  of the base  100  generally corresponds to the second side  38  of the test fixture  30 , and the bottom  112  of the base  100  generally corresponds to the bottom  42  of the test fixture  30 . 
         [0041]    A first channel  114  of the base  100  extends between the first end  102  and the second end  104 . Likewise, a second channel  116  extends between the first end  102  and the second end  104 . The first channel  114  includes a bottom  114   b  and a pair of walls  114   w  adjacent each side of the bottom  114   b.  Likewise, the second channel  116  includes a bottom  116   b  and a pair of walls  116   w  adjacent each side of the bottom  116   b.  The base  100  further includes a channel  118  that extends between the first end  102  and the second end  104 . As depicted, the channel  118  is a center channel. The channel  118  is positioned between the channels  114  and  116 . The channel  118  includes a bottom  118   b  and a pair of walls  118   w  adjacent each side of the bottom  118   b.  As depicted, the channels  114 ,  116 ,  118  open toward the top  110  of the base  100 . The base  100  further includes a first relief  120  and a second relief  122 . As depicted, the reliefs  120 ,  122  open toward the bottom  112 . 
         [0042]    The base  100  further includes a series of holes  124  (e.g., top holes). As depicted, the holes  124  open toward the top  110  of the base  100 . The holes  124  are arranged in rows. A first row of holes  124   a  is positioned between the first side  106  and the first channel  114 . A second row of holes  124   b  is positioned between the first channel  114  and the channel  118 . A third row of holes  124   c  is positioned between the channel  118  and the second channel  116 . A fourth row of holes  124   d  is positioned between the second channel  116  and the second side  108 . 
         [0043]    The base  100  further includes a series of holes  126  (e.g., end holes). As depicted, the holes  126  generally open toward the first end  102 . A first hole  126   a  is positioned between the first side  106  and the first channel  114 . A second hole  126   b  is positioned between the first channel  114  and the channel  118 . A third hole  126   c  is positioned between the channel  118  and the second channel  116 . A fourth hole  126   d  is positioned between the second channel  116  and the second side  108 . As depicted, the holes  124 ,  126  are threaded holes that are used for fastening other components to the base  100 . 
         [0044]    The base  100  further includes holes  128  at the channels  114 ,  116 ,  118 . In particular, a first set of holes  128   a  is positioned at the bottom  114   b  of the first channel  114 . Likewise, a second set of holes  128   c  is positioned at a bottom  116   b  of the second channel  116 . Likewise, a third set of holes  128   b  is positioned at the bottom  118   b  of the channel  118 . As depicted, the holes  128  provide openings between the top  110  and the bottom  112  of the base  100 . The holes  128  may be used as drain holes to drain fluids from the channels  114 ,  116 ,  118 . 
         [0045]    The base  100  further includes a pair of stacking holes  130 . The stacking holes  130  are located adjacent the second end  104  of the base  100  and are also located adjacent the first side  106  and the second side  108 , respectively. Each of the stacking holes  130  includes a hole bottom  132 . 
         [0046]    Turning now to  FIGS. 6 and 7 , the stationary portion  200  of the test fixture  30  will be described in detail. The stationary portion  200  extends from a first end  202  to a second end  204 . As depicted, the second end  204  generally corresponds to the second end  34  of the test fixture  30 . The stationary portion  200  further includes a first side  206 , a second side  208 , a top  210 , and a bottom  212 . As depicted, the first side  206  generally corresponds to the first side  36  of the test fixture  30 , the second side  208  generally corresponds to the second side  38  of the test fixture  30 , and the bottom  212  of the stationary portion  200  generally abuts the top  110  of the base  100 . 
         [0047]    The stationary portion  200  includes a first series of slots  214 . The first slots  214  are generally aligned and extend in a direction between the first and the second ends  202 ,  204 . The first slots  214  include slots  214   a,    214   b,    214   c,    214   d,  and  214   e.  The first slots  214   a - e  are positioned in a row with the slot  214   a  nearest the first end  202  and the slot  214   e  nearest the second end  204 . The stationary portion  200  further includes a second series of slots  216 . The second slots  216  are generally aligned and extend in the direction between the first and the second ends  202 ,  204 . The second slots  216  include slots  216   a,    216   b,    216   c ,  216   d,  and  216   e.  The second slots  216   a - e  are positioned in a row with the slot  216   a  nearest the first end  202  and the slot  216   e  nearest the second end  204 . The stationary portion  200  further includes a third series of slots  218 . The third slots  218  are generally aligned and extend in the direction between the first and the second ends  202 ,  204 . The third slots  218  include slots  218   a,    218   b,    218   c,    218   d,  and  218   e.  The third slots  218   a - e  are positioned in a row with the slot  218   a  nearest the first end  202  and the slot  218   e  nearest the second end  204 . The first slots  214  are positioned adjacent the first side  206 . The second slots  216  are positioned adjacent the second side  208  of the stationary platform  200 . The third slots  218  are positioned between the slots  214  and the slots  216 . The first slots  214  generally correspond with the first channel  114  of the base  100 . Likewise, the second slots  216  generally correspond with the second channel  116  of the base  100 . Likewise, the third slots  218  of the stationary portion  200  generally correspond with the channel  118  of the base  100 . 
         [0048]    The stationary portion  200  further includes a first stacking pin hole  220  and a second stacking pin hole  222 . The first stacking pin hole  220  is positioned adjacent the first side  206  and also adjacent the second end  204 . The second stacking pin hole  222  is positioned adjacent the second side  208  and positioned adjacent the second end  204 . 
         [0049]    The stationary portion  200  further includes a series of mounting holes  224 . The mounting holes  224  are arranged in a series of rows. A first series of mounting holes  224   a  is positioned between the first slots  214  and the first side  206 . The mounting holes  224   a  generally correspond with the holes  124   a  of the base  100 . A second series of mounting holes  224   b  is positioned between the first slots  214  and the third slots  218 . The mounting holes  224   b  generally correspond with the holes  124   b  of the base  100 . A third series of mounting holes  224   c  is positioned between the third slots  218  and the second slots  216 . The mounting holes  224   c  generally correspond with the holes  124   c  of the base  100 . A fourth series of mounting holes  224   d  is positioned between the second slots  216  and the second side  208  of the stationary portion  200 . 
         [0050]    In the depicted embodiment, a scale  226  is positioned adjacent the slot  218   e , as shown at  FIG. 7 . As depicted, an indicator mark  228  is positioned adjacent the slot  218   a,  as illustrated at  FIG. 7 . 
         [0051]    As depicted, the slots  214 ,  216 ,  218  and the holes  224  of the stationary portion  200  are included in a plate  230  of the stationary portion  200 . The plate  230  generally extends between the first end  202  and the second end  204 . The plate  230  also extends between the first side  206  and the second side  208  of the stationary portion  200 . The plate  230  also extends from the bottom  212  of the stationary portion  200  to a top surface  230   t  of the plate  230 . 
         [0052]    The stationary portion  200  further includes a first series of pin holes  232  and a second series of pin holes  234 . As depicted, the first and the second series of pin holes  232 ,  234  are included in the plate  230 . The first series of the pin holes  232  includes a first pin hole  232   a,  a second pin hole  232   b,  a third pin hole  232   c,  a fourth pin hole  232   d,  and a fifth pin hole  232   e.  The pin holes  232  are generally aligned with the slots  214 . The pin hole  232   a  is positioned between the slots  214   a  and  214   b.  The pin hole  232   b  is positioned between the slots  214   b  and  214   c.  The pin hole  232   c  is positioned between the slots  214   c  and  214   d.  The pin hole  232   d  is positioned between the slots  214   d  and  214   e.  And, the pin hole  232   e  is positioned between the slot  214   e  and the second end  204  of the stationary portion  200 . The second series of the pin holes  234  includes a first pin hole  234   a,  a second pin hole  234   b,  a third pin hole  234   c,  a fourth pin hole  234   d,  and a fifth pin hole  234   e.  The pin holes  234  are generally aligned with the slots  216 . The pin hole  234   a  is positioned between the slots  216   a  and  216   b.  The pin hole  234   b  is positioned between the slots  216   b  and  216   c.  The pin hole  234   c  is positioned between the slots  216   c  and  216   d.  The pin hole  234   d  is positioned between the slots  216   d  and  216   e.  And, the pin hole  234   e  is positioned between the slot  216   e  and the second end  204  of the stationary portion  200 . 
         [0053]    The stationary portion  200  includes a first series of fixed pins  236  and a second series of fixed pins  238 . As depicted, the first series of fixed pins  236  includes a first pin  236   a,  a second pin  236   b,  a third pin  236   c,  a fourth pin  236   d,  and a fifth pin  236   e.  The first series of the fixed pins  236  are positioned within the corresponding pin holes  232 . As depicted, the second series of the fixed pins  238  includes a first pin  238   a,  a second pin  238   b , a third pin  238   c,  a fourth pin  238   d,  and a fifth pin  238   e.  The second series of the fixed pins  238  are positioned within the corresponding pin holes  234 . A pin  240  is illustrated at  FIG. 8 . The pin  240  can be used as the fixed pins  236   a - e  and the fixed pins  238   a - e . The pin  240  extends between a first end  242  and a second end  244 . The pin  240  includes a first diameter  246  adjacent the first end  242 . As illustrated, the first diameter  246  is chamfered at the first end  242 . The pin  240  also includes a second diameter  248  adjacent the second end  244 . As depicted, the second diameter  248  is chamfered at the second end  244 . As depicted, the first diameter  246  and the second diameter  248  are concentric with each other. A shoulder  250  is positioned between the first diameter  246  and the second diameter  248 . In a preferred embodiment, the pin holes  232 ,  234  are sized for a press fit (i.e., an interference fit) with the first diameter  246  of the pin  240 . As depicted, the first diameter  246  is inserted into the pin holes  232 ,  234  until the shoulder  250  abuts the top  230   t  of the plate  230 . 
         [0054]    Turning now to  FIG. 9 , the moveable portion  300  will be described in detail. The moveable portion  300  extends between a first end  302  and a second end  304 . The moveable portion  300  also includes a first side  306 , a second side  308 , a top  310 , and a bottom  312 . As depicted, the moveable portion  300  includes a threaded hole  314  at the first end  302 . The threaded hole  314  extends between the first end  302  and a slot  316  (e.g., a relief slot). As depicted, the moveable portion  300  includes a bar  330 . The bar  330  extends generally between the first end  302  and the second end  304 . The bar  330  also extends between the first side  306  and the second side  308 . The bar  330  extends generally between the bottom  312  of the moveable portion  300  and a top surface  330   t  of the bar  330 . The moveable portion  300  includes a series of pin holes  332 . As depicted, the pin holes  332  are included in the bar  330 . As depicted, the pin holes  332  include a first pin hole  332   a,  a second pin hole  332   b,  a third pin hole  332   c,  a fourth pin hole  332   d,  and a fifth pin hole  332   e.    
         [0055]    The moveable portion  300  includes moveable pins  336 . In particular, the moveable pins  336  include a first moveable pin  336   a,  a second moveable pin  336   b,  a third moveable pin  336   c,  a fourth moveable pin  336   d,  and a fifth moveable pin  336   e.  The moveable pins  336   a - e  are mounted in the corresponding pin holes  332   a - e . The pins  336  can be straight pins with no shoulders. The mounting of the moveable pins  336  can include pressing the pins  336  into the pin holes  332 . The moveable pins  336  extend between a first end  342  and a second end  344 . The moveable pins  336  include a diameter  346 . In preferred embodiments, the diameter  346  is pressed into the pin hole  332  until the first end  342  is flush (i.e., even) with the bottom  312  of the moveable portion  300 . 
         [0056]    Turning now to  FIGS. 10-14 , the adjustment bracket  400  will be described in detail. The adjustment bracket  400  extends between a first end  402  and a second end  404 . As depicted, the first end  402  generally corresponds to the first end  32  of the test fixture  30 , and the second end  404  generally abuts the first end  102  of the base  100 . The adjustment bracket  400  also includes a first side  406 , a second side  408 , a top  410 , and a bottom  412 . As depicted, the first side  406  generally corresponds to the first side  36  of the test fixture  30 , the second side  408  generally corresponds to the second side  38  of the test fixture  30 , the top  410  generally corresponds to the top surface  230   t  of the plate  230 , and the bottom  412  generally corresponds to the bottom  42  of the test fixture  30 . 
         [0057]    The adjustment bracket  400  includes a hole  414  (i.e., an actuator hole). As depicted, the hole  414  is centered between the first side  406  and the second side  408 . The adjustment bracket  400  further includes a counter-bore  416  positioned concentric with the hole  414 . The counter-bore  416  opens toward the first end  402  of the adjustment bracket  400 . The counter-bore  416  defines a shoulder  418  upon meeting the hole  414 . The adjustment bracket  400  further includes a first stacking pin hole  420  and a second stacking pin hole  422 . The stacking pin holes  420 ,  422  open toward the top  410  of the adjustment bracket  400 . The adjustment bracket  400  further includes a set of holes  426  (e.g., end holes). In particular, the holes  426  include a first hole  426   a,  a second hole  426   b,  a third hole  426   c , and a fourth hole  426   d.  The holes  426  correspond with the holes  126  of the base  100 . As depicted, each of the holes  426  includes a countersink  428 . The adjustment bracket  400  further includes a pair of stacking holes  430 . The stacking holes  430  open toward the bottom  412  of the adjustment bracket  400 . The stacking holes  430  are positioned adjacent the first side  406  and the second side  408  of the adjustment bracket  400 . Each of the stacking holes  430  includes a hole bottom  432 . The adjustment bracket  400  further includes an actuator retainer notch  434 . The actuator retainer notch  434  includes a bottom  434   b  and a pair of walls  434   w  adjacent each side of the bottom  434   b.  The adjustment bracket  400  further includes a relief  436 . As depicted, the relief  436  is positioned adjacent the top  410  and the second end  404 . The relief  436  includes a bottom  436   b  and a side  436   s  (see  FIG. 14 ). The bottom  436   b  generally abuts a portion of the bottom  212  of the stationary portion  200  adjacent the first end  202  of the stationary portion  200 . The side  436   s  generally abuts the first end  202  of the stationary portion  200 . 
         [0058]    Turning now to  FIG. 15 , the actuator  500  will be described in detail. As depicted, the actuator  500  is a screw. The actuator  500  extends between a first end  502  and a second end  504 . The actuator  500  includes a head  506  positioned at the first end  502 . The head  506  includes a diameter  508  and a drive attachment  510 . In the depicted embodiment, the drive attachment  510  is a slot (e.g., a screwdriver slot). A reduced diameter portion  512  is positioned adjacent the head  506 . A shoulder  514  is defined between the diameter  508  and the diameter  512 . The reduced diameter portion  512  includes a groove  516 . A bottom of the groove  516  defines a diameter  518 . The groove  516  extends between a first wall  520  and a second wall  522 . The reduced diameter  512  terminates at a shoulder  524 . A threaded portion  526  extends between the shoulder  524  and the second end  504 . 
         [0059]    Turning now to  FIG. 16 , the preloading member  540  will be described in detail. As depicted, the preloading member  540  is a wave washer. The preloading member  540  extends between a first side  542  and a second side  544 . The preloading member  540  further defines an inner diameter  546  and an outer diameter  548 . 
         [0060]    Turning now to  FIG. 17 . The keeper  560  will be described in detail. The keeper  560  extends between a first side  562  and a second side  564  (see  FIG. 2 ). The keeper  560  further includes a first edge  566 , a second edge  568 , a top  570 , and a bottom  572 . The keeper  560  includes a slot  574 . As depicted, the slot  574  is centered between the first edge  566  and the second edge  568 . The slot  574  extends through the bottom  572 . A radius  576  is defined at an end of the slot  574 . 
         [0061]    Turning now to  FIGS. 18-20 . The support pin assembly  600  will be described in detail. The support pin assembly  600  extends from a top  602  to a bottom  604 . As depicted, the support pin assembly  600  includes a support pin  610 , a plunger  640 , and a spring  680 . 
         [0062]    The support pin  610  extends from a top  612  to a bottom  614 . The support pin  610  defines a pin diameter  616  adjacent to the top  602 . As depicted, a radius  618  is defined between the pin diameter  616  and the top  612  of the support pin  610 . The support pin  610  includes a flange  620  adjacent the bottom  614 . The support pin  610  includes a bore  622  that opens toward the bottom  614 . As depicted, the bore  622  is concentric with the pin diameter  616 . The bore  622  defines an inner diameter  624 . The bore  622  includes a bottom  626 . A chamfer  628  is defined between the bore  622  and the bottom  614 . 
         [0063]    The plunger  640  extends between a first end  642  and a second end  644 . The plunger  640  includes a diameter  646  adjacent the first end  642 . The plunger  640  includes a flange  648  adjacent the second end  644 . In the depicted embodiment, the flange  648  defines a diameter  650 . A radius  652  is defined between the diameter  650  and the second end  644 . A radius  654  is defined between the diameter  650  and a shoulder  656 . The shoulder  656  is positioned between the diameter  646  and the diameter  650 . The diameter  646  of the plunger  640  is sized to have a slip fit with the inner diameter  624  of the support pin  610 . 
         [0064]    The spring  680  extends between a first end  682  and a second end  684 . The support pin assembly  600  is assembled by positioning the spring  680  within the bore  622  and abutting the first end  682  of the spring  680  against the bottom  626  of the bore  622 . Upon the insertion of the spring  680  into the bore  622 , the first end  642  of the plunger  640  is inserted into the bore  622  of the support pin  610 . The first end  642  abuts the second end  684  of the spring  680 . Upon the insertion of the first end  642  of the plunger  640  into the bore  622 , the spring  680  is compressed. The plunger  640  is thereby spring-loaded to extend away from the bottom  614  of the support pin  610 . 
         [0065]    The assembly and operation of the test fixture  30  will now be described in detail. To assemble the test fixture  30 , the moveable portion  300  may be assembled into the channel  118  of the base  100 . In particular, the first side  306  and the second side  308  are positioned adjacent the pair of the walls  118   w  of the channel  118 . The bottom  312  of the moveable portion  300  may be positioned adjacent the bottom  118   b  of the channel  118 . The moveable portion  300  is oriented such that the first end  302  is positioned toward the first end  102  of the base  100  and the second end  304  is positioned toward the second end  104  of the base  100 . The spacing between the first side  306  and the second side  308  of the moveable portion  300  is sized for a sliding fit between the walls  118   w  of the channel  118 . Thus, the moveable portion  300  forms a moveable slide with respect to the base  100 . 
         [0066]    The support pin assembly  600  may be inserted into the slots  214 ,  216  of the stationary portion  200 . The support pin assembly  600  is oriented such that the flange  620  is positioned adjacent the bottom  212  of the stationary portion  200 . The pin diameter  616  of the support pin assembly  600  protrudes through the slots  214 ,  216 . In the depicted embodiment, there are a total of ten of the slots  214 ,  216  and there are a total of ten support pin assemblies  600 . One support pin assembly  600  is assembled to each of the slots  214 ,  216 . The stationary portion  200 , with the support pin assemblies  600  inserted, may be positioned over and attached to the base  100 , with the moveable portion  300  inserted. The mounting holes  224  of the stationary portion  200  are aligned with the corresponding holes  124  of the base  100 . A set of fasteners  702  may be inserted through the holes  224  and screwed into the holes  124 . The stationary portion  200  is thereby attached to the base  100 , with the moveable portion  300  and the support pin assemblies  600  trapped between them. 
         [0067]    Upon assembling the stationary portion  200  to the base  100 , the springs  680  of the support pin assemblies  600  are compressed. The flange  620  of each of the support pin assemblies  600  is thereby held in contact with the bottom  212  of the stationary portion  200 . In addition, the second end  644  of the plunger  640  is thereby held in contact with the bottom  114   b,    116   b  of their respective channel  114 ,  116 . The contact between the flange  620  and the plate  230  and the contact between the second end  644  and the bottom  114   b,    116   b  keeps the support pin  610  oriented perpendicular to the top surface  230   t  of the plate  230 . The contact also provides friction that keeps the support pin assembly  600  in place. To move the support pin assembly  600 , the support pin  610  can be slid along the slots  214 ,  216  by overcoming the friction. In certain embodiments, the support pin assembly  600  may be moved by depressing the support pin  610  and thereby further compressing the spring  680 . Upon the compression being released between the flange  620  and the bottom  212  of the stationary portion  200 , the support pin assembly  600  may be moved along the slots  214 ,  216 . Frictional characteristics of the support pin assembly  600  may be adjusted appropriately to give a desired combination of holding power and moveablility. The spring  680  may be selected to tailor the desired holding power and moveability of the support pin assembly  600 . 
         [0068]    As the stationary portion  200  is positioned over and fastened to the base  100 , the moveable pins  336  are inserted into the slots  218 , correspondingly. Upon assembly of the base  100 , the stationary portion  200 , the moveable portion  300 , and the support pin assemblies  600 , the moveable portion  300  may be slid along the channel  118 , with each of the moveable pins  336  positioned within the slots  218 , correspondingly. 
         [0069]    To control the position of the moveable portion  300  relative to the stationary portion  200 , the actuator  500  may be adjusted and/or set. To install the actuator  500  to the test fixture  30 , the actuator  500 , the adjustment bracket  400 , the preloading member  540 , and the keeper  560  may be preassembled. The actuator  500  is first fitted with the preloading member  540 . In the depicted embodiment, two of the preloading members  540  are used. The inner diameter  546  of the preloading member  540  is positioned over the diameter  512  of the actuator  500  and positioned adjacent the shoulder  514 . The second end  504  of the actuator  500  may now be inserted through the counter-bore  416  and then through the hole  414 . The actuator  500  is further slid through the hole  414  until the preloading members  540  become compressed between the shoulder  418  and the shoulder  514 . The groove  516  is now positioned in the actuator retainer notch  434 . The slot  574  of the keeper  560  is now positioned within the groove  516  straddling the diameter  518 . 
         [0070]    Upon the keeper  560  being positioned within the groove  516 , the actuator  500  is attached to the adjustment bracket  400 . However, the actuator  500  is free to rotate within the hole  414 . When sliding the keeper  560  in the groove  516 , the edges  566 ,  568  of the keeper  560  are positioned adjacent the walls  434   w  of the actuator retainer notch  434 . Upon assembly, the top  570  of the keeper  560  is preferably positioned adjacent the relief  436  of the adjustment bracket  400 . The adjustment bracket  400 , with the actuator  500  sub-assembled, may now be attached to the base  100 . The relief  436  is positioned adjacent the stationary portion  200 . In particular, the first end  202  of the stationary portion  200  overhangs the first end  102  of the base  100 . The holes  426  are aligned to the corresponding holes  126  of the base  100 . A set of fasteners  700  may be inserted through the holes  426  and threaded into the holes  126 . The adjustment bracket  400  is now secured to the test fixture  30 . The keeper  560  is trapped between the overhanging portion of the stationary portion  200  and the groove  516  of the actuator  500 . 
         [0071]    In certain embodiments, the threads  526  of the actuator  500  are engaged with the threaded hole  314  of the moveable portion  300  during the assembly process. In other embodiments, the adjustment bracket  400  may be secured to the base  100  first and then the threads  526  of the actuator  500  may be engaged with the threaded hole  314  of the moveable portion  300 . In either case, upon the threads  526  of the actuator  500  engaging the threaded hole  314  of the moveable portion  300 , the position of the moveable portion  300  may be controlled by the actuator  500 . It should be noted that the preloading member  540  may provide a zero-backlash position to the actuator  500  within the adjustment bracket  400 . The threads  526  and the threaded hole  314  may incorporate standard machine threads, ACME profile threads, ball screw threads, or other threads that are known in the art. The threads  526  and the threaded hole  314  may either be threaded right-handed or left-handed. The connection between the threads  526  and the threaded hole  314  may be zero-backlash or low backlash. 
         [0072]    As mentioned above,  FIGS. 26 and 27  illustrate the testing of one of the specimens  800 ,  900 , respectively. The test fixture  30 , as illustrated at the figures, may test between one and five specimens simultaneously.  FIG. 28  illustrates the test fixture  30  testing five of the specimens  800  simultaneously. In other embodiments, the test fixture  30  may be able to accommodate additional test specimens simultaneously. The test specimens  800 ,  900  may be different test specimens in different tests. In preferred embodiments, the test specimens tested by the test fixture  30  in a given test may be identical to each other. In particular, the test specimens in a given test may be made of the same material, and the test specimens in a given test may be of the same thickness. 
         [0073]    In the depicted embodiment, the pins  236 ,  238 ,  336 , and  610  are material engaging components that engage the test specimens  800 ,  900 . As depicted, the material engaging components are material engaging pins. In other embodiments, the material engaging components can take other forms. In the depicted embodiment, the pins  236 ,  238 ,  336 , and  610  are cantilevered pins with a free end and a supported end. In the depicted embodiment, the free ends of the cantilevered pins are positioned on the same side (e.g., the top) of the test fixture  30 , and the supported ends are all positioned on the same side (e.g., the bottom) of the test fixture  30 . Having the free ends configured together allows easy loading and unloading of the test specimens  800 ,  900  from an open side (e.g., the top) of the test fixture  30  with the free ends. 
         [0074]    A method of using the test fixture  30  to test the test specimens  800  or  900  will now be described in detail. The test fixture  30  may be initially set at the first configuration  44 . The test fixture  30  may be able to accommodate a variety of thicknesses of various test specimens in various test setups. In preferred embodiments, the same thickness of test specimens is used throughout the test fixture  30  in a given test. As depicted, the test specimen  800  has a thickness T 1  between a first side  802  and a second side  804  of the test specimen  800 . Likewise, the test specimen  900  has a thickness T 2  between a first side  902  and a second side  904  of the test specimen  900 . In the depicted examples, the thickness T 1  is greater than the thickness T 2 . The range of thicknesses accommodated by the test fixture  30  may be limited by a space T M  between corresponding pins  236 ,  238  and the corresponding support pin assembly  600  (see  FIG. 21 ). The test specimen may be loaded into the test fixture  30 , configured to the first configuration  44 , by inserting the test specimen between the pins  236 ,  238  and the corresponding support pin assembly  600  (e.g., from the open side). One or both of the support pin assemblies  600  may now be slid toward the corresponding pins  236 ,  238  until the test specimen is sandwiched between them. As depicted, a bottom  812  of the test specimen  800  or a bottom  912  of the test specimen  900  abut the top surface  230   t  of the plate  230  when the test specimens  800  or  900  are loaded into the test fixture  30 . The test specimen  800  extends between a first end  806  and a second end  808 . Likewise, the test specimen  900  extends between a first end  906  and a second end  908 . A distance between the first ends  806 ,  906  and the second ends  808 ,  908  is preferably greater than the distance D S  and includes enough excess length to accommodate the deformed profile of P 1 , P 2  of the test specimens  800 ,  900 . 
         [0075]    Upon loading the test specimens  800  or  900  into the test fixture  30 , the actuator  500  may be adjusted as desired to impart the desired profile P 1 , P 2  to the test specimens  800 ,  900 . The scale  226  and/or the indicator  228  may give an indication of the configuration of the test fixture  30 . In addition, other instruments may be used to determine if the configuration of the test fixture  30  matches the desired configuration and in setting the test fixture  30  to the desired configuration. For example, a measurement may be taken with calipers between a reference surface and one of the moveable pins  336  and/or the moveable portion  300 . As illustrated at  FIG. 22 , a measurement M is taken between the second end  304  of the moveable portion  300  (i.e., the slide) and the second end  34  of the test fixture  30 . 
         [0076]    The test specimens  800 ,  900  may have a width that extends generally perpendicular to the top surface  230   t  of the plate  230 . In particular, the test specimen  800  has a width that extends from the bottom  812  to a top  810  of the test specimen  800 . Likewise, the test specimen  900  has a width that extends from the bottom  912  to a top  910  of the test specimen  900 . In preferred embodiments, the tops  810 ,  910  of the test specimens  800 ,  900  are below the top  310  of the moveable portion  300  and the top  210  of the stationary portion  200 . 
         [0077]    In the depicted embodiment, the test fixture  30  can be stacked on top of another test fixture  30 . In this way, multiple test fixtures  30  can be positioned one on top of the other to facilitate multiple tests using multiple test fixtures  30 . A pair of the stacking pins  704  are inserted into the first and the second stacking pin holes  220 ,  222  of the stationary portion  200 . Another pair of the stacking pins  704  is inserted into the first and the second stacking pin holes  420 ,  422  of the adjustment bracket  400 . To stack the additional test fixture  30  on the stacking pins  704 , the stacking holes  130  of the base  100  and the stacking holes  430  of the adjustment bracket  400  are positioned over free ends of the stacking pins  704 . The hole bottoms  132  of the stacking holes  130  and the hole bottoms  432  of the stacking holes  430  come to rest on the free ends of the stacking pins  704 . 
         [0078]    In certain embodiments, the test fixture  30  may be used in conjunction with other tests (e.g., chemical tests). To accommodate such tests, materials used in the test fixture  30  are preferably compatible and not reactive with components of the other tests. In the depicted embodiment, the test fixture  30  is made of stainless steel materials that resist reaction with certain chemicals. The test fixture  30 , along with the test specimens  800  or  900 , may be submerged in a tank containing a liquid chemical. 
         [0079]    In the present disclosure, references are made to various orientations (e.g., top, bottom, side, etc.). It will be appreciated that these references are not limiting references and that various embodiments of the present disclosure may have some or all of these references reoriented. In the present disclosure, references are made to the mobility of certain components (e.g., stationary, moveable, etc.). It will be appreciated that these references are not limiting references and that various embodiments of the present disclosure may have other mobility for some or all of these components. 
         [0080]    Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the scope of this disclosure is not to be unduly limited to the illustrative embodiments set forth herein.