Determination of Elastic Plastic Fracture Toughness Parameters for a Compact Tension Specimen Using the Finite Element Method

In this study, elastic-plastic fracture toughness of an aluminum alloy is investigated. J-integral was calculated using the finite element software and formulation. Crack tip opening displacement (CTOD) is determined by using the plastic hinge model (delta(ph)) and direct measurement (delta(5)). J-Delta a and CTOD-Delta a resistance curves are constructed and compared with those obtained from formulation and those generated from test data, respectively. Good agreement has been obtained between the test results, the formulation and the results of the finite element analysis. The relationship between delta(ph) and delta(5) is nonlinear and as CTOD increases delta(5) becomes larger than delta(ph). The relationship between J-integral and CTOD is found to be linear for both delta(ph) and delta(5). It has been seen that the proportionality constant d(n) considerably depends on the method of calculation of CTOD