The influence of gripping techniques on the tensile properties of tendons.

Gripping is a major challenge faced in the tensile testing of tendons. As soft and aqueous materials, tendons are prone to slip and experience premature failure during mechanical testing. Several gripping methods were attempted and evaluated, including serrated jaw, sandpaper, frozen ends, and air-dried ends. It was found that 1 kN pneumatic grips (Shimadzu Company) lined with cardboard provided an adequate grip without perceptible slip and damage to the tendons. It was found that using the pneumatic grips with cardboard lining the stress concentration at the grip-specimen interface reduced substantially. An analysis of specimens that failed at the grip-specimen interface versus those that failed at mid-substance shows that there was no significant difference in their tensile properties.