On the simulation of creep crack growth by means of grain-elements

摘要

A new computational technique is discussed to analyze intergranular creep crack growth in a discrete manner. A standard contimuum FEM description is matched to a crack tip region in which grains are represented individually by so-called grain elements, and grain boundaries by special interface-elements. These grain boundary elements incorporate grain boundary sliding and the nucleation and creep-diffusive grwoth of cavities till coalescence and microcracking. SOme preliminary results are presented for C~* controlled, Mode I creack growth under small-scale damage conditions. Particular a ttention is focussed on conditions leading to brittle or ductile crack grwoth.