The criterion of critical void growth ratio and its applications

In the present paper, the new material parameter of ductile fracturev_gc with an obvious microscopic physical meaning is emphasized, which can be determined by macroscopic method. The theoretical and experimental background for the criterion of critical void growth ratio is expounded from both macroscopic and microscopic points of view. The relationship between the macroform parameterv_gc and microform oneR_c/R_go of critical void growth ratio is investigated. The engineering experimental procedure for determining the value ofv_gc of materials has been recommended. The values ofv_gc for some materials with different heat treatments have been estimated. It is found that the parameterv_gc can be effectively used for selecting materials and their heat treatments. A modified ASPEF criterion accounting for stress states has been proposed. Related expression of modified ASPEF andv_gc has been derived.