A Simplified Small Scale Yielding Estimate Method for Determination of Second Elastic-Plastic Fracture Mechanics Parameter

Abstract

Two-parameter approaches of elastic-plastic fracture mechanics (EPFM) are used to analyze structure fracture more accurately, especially for the conditions with low crack constraint. A small scale yielding estimate method has been developed by authors previously to conveniently and effectively determine the values of constraint (second) parameter in the J-A two parameter approach under small scale yielding conditions to enable extensive theoretical investigation and engineering application of J-A approach, e.g. the fracture analysis of wind velocity sensor supporting structure. In current work, based on the shape similarity of relation curves between constrain parameter $A$ and $T$ stress, an alternative simplified formation of the previously developed small scale yielding method is suggested to predict the constraint parameter values more conveniently and quickly. The suggested simplified formation of constrain parameter estimate method is validated through comparing predicted $A$ values with their finite element analysis (FEA) results of three mode I crack specimens, single edge cracked plate (SECP), center cracked plate (CCP) and double edge cracked plate (DECP), with various crack depth and hardening exponents.