Effect of Strain Hardening on the Estimation of J-Integral in Compact Tension Specimens

Compact tension (CT) specimen testing is used to compute the fracture toughness parameter J-integral for different materials using load-displacement curve. In this work, J is investigated for compact tension specimen for a strain-hardening material using plastic limit-load analysis. The hardening effect is accounted for through a simple linear hardening curve using a lower bound approach. Analytic expression for fracture parameters are derived from basic formulation. Results illustrated for different cases show that as the material strain hardening increases, the J-Integral increases especially for shallow crack specimens.