EFFECT OF STRAIN-DEPENDENT COHESIVE ZONE MODEL ON PREDICTIONS OF CRACK-GROWTH RESISTANCE

Crack growth in an elastic-plastic solid is studied by a computational model, in which a cohesive zone model is used to characterize the fra cture process. The separation work per unit area and the peak stress r equired for separation are the basic parameters in the cohesive zone m odel, but also an effect of plastic straining, reducing the peak stres s for separation, is incorporated here. This additional effect represe nts acceleration of the void growth process and nucleation of more voi ds, resulting from intense plastic straining in the immediate vicinity of the crack tip. The analyses are carried out for conditions of smal l-scale yielding under plane strain, with the mode I stress intensity factors specified al the loading parameter. Also the effect of a T-str ess on crack growth resistance is investigated. Copyright (C) 1996 Els evier Science Ltd.