Patent ID: 8225675

Claim:
A fixture for imposing shear stresses on a material, comprising: a first block disposed adjacent a base surface and having a first test specimen mounting portion with a first attaching mount for receiving a first test specimen and a first reference surface disposed at a first angle to the base surface and a second test specimen mounting portion disposed distal from the first test specimen mounting portion, the second test specimen mounting portion having a second attaching mount for receiving a second test specimen and a second reference surface disposed at a second angle to the base surface, where the second angle is supplementary to the first angle, wherein the first test specimen mounting portion and the second test specimen mounting portion are substantially immovably fixed with respect to each other; and a second block disposed offset from the base surface and between the first test specimen mounting portion and the second test specimen mounting portion, the second block having a third test specimen mounting portion having a third attaching mount for receiving the first test specimen, and a fourth attaching mount for receiving the second test specimen, and a third reference surface disposed adjacent the first reference surface at substantially the first angle to the base surface, and a fourth reference surface disposed adjacent the second reference surface at substantially the second angle to the base surface such that when (a) the first test specimen is disposed in the first attaching mount and the third attaching mount and (b) the second test specimen is disposed in the second attaching mount and the fourth attaching mount, the second block moves with respect to the first block when a downward loading force is applied to the second block.