AN ANALYTICAL STUDY OF VOID GROWTH IN VISCOPLASTIC SOLIDS

Detailed numerical analyses are conducted to examine the effect of mat erial elasticity and nonlinear shape changes on void growth in viscopl astic solids. Numerical simulations are carried out under constant str ess as well as cyclic loading conditions. The material response is ass umed to be elastic-nonlinear viscous (power law creep). Analyses of vo id growth are conducted assuming creep-controlled mechanism. The role of finite geometry changes in understanding cavity growth under balanc ed strain-controlled cyclic loading is also explored. The results indi cate that while elastic accommodation does not influence void growth, non-linear shape changes of the voids significantly affect their growt h characteristics. It is also shown that while grain boundary voids ca n grow under balanced strain cyclic loading when the accompanying shap e changes are accounted for, they can either shrink or grow under load -controlled cycling depending on the loading frequency.