Experimental evaluation of the fracture toughness (K1c) of an epoxy resin

Abstract

Fracture-toughness tests were conducted on Araldite CT 200, in order to obtain K_1c, the plane-strain, mode 1 critical stress-intensity factor. Two essentially different methods were used, namely the photoelastic method and the quasistatic energy method. In the photoelastic method, stress fringe patterns were analysed at load intervals up to failure and the stress-intensity coefficients obtained were compared with those from the boundary collocation method. In the energy method, two types of specimen geometry were tested, resulting in stable crack propagation. Good correlation was obtained between the two methods.