APPLICATION OF 2-PARAMETER ELASTIC-PLASTIC FRACTURE-MECHANICS TO ANALYSIS OF STRUCTURES

J-integral resistance curves are developed for single edge bend [SE(B) ] specimens of HY80 over a range of crack length ratios from 0.13 to 0 .83. The wide range of constraint present over this range of crack len gth ratios results in J-integral resistance curves with nearly constan t initiation toughnesses as measured by J(Ic), but with widely varying J-R curve slopes beyond J(Ic). A nearly linear relationship is shown to exist between the slope of the material J-resistance curve after 1 mm of crack extension and the Q parameter introduced by O'Dowd and Shi h (Family of crack-tip fields characterized by a triaxiality parameter : Part I - Structure of fields. Journal of Mechanics and Physics of So lids, 1991, 39(8), 989-1015) to quantify elastic-plastic constraint. T he constancy of J(Ic) and the linear dependence of the tearing resista nce on Q is used to develop an interpolation scheme to evaluate the J- integral resistance curve applicable to a specific structural applicat ion when the Q parameter can be estimated for the flaw geometry and lo ading present in the application. Published by Elsevier Science Ltd.