Figure 3

Torsion (T) applied by transmitting equal but opposite components of force to hardened steel shoulder bolts on the lateral and medial side of each fixture, with the option to apply an axial bias load (F). This allowed unconstrained 3D relative movement of the test specimen ends, and produced uniform load over the entire length of the specimen. Insert: view of hardened steel sphere free to move in a CrCa spherical slot in each loading fixture base keeping the fixture centered LM while allowing all CrCa components of force to be transmitted through the pair of shoulder bolts.