Theoretical, experimental and computational mechanics of fracture in constrained interlayers

The constraint of a thin silver interlayer is used to create high triaxial stresses to evaluate the applicability of theoretical models for ductile fr acture. Rice and Tracey's model for cavity expansion under high triaxial st ates of stress and Huang et al.'s model for cavity instability were conside red. The experimentally determined sigma(m)/sigma(y) values suggest that fu rther investigation of the Huang et al. theory is warranted. Microstructura l analysis revealed that multiple cavities were initially present in the si lver interlayers, and the number and size of the cavities increased as fail ure was approached. Finite element analysis and experimental results showed excellent agreement in a computational determination of cavity instability . Thus, it appears that ductile fracture in constrained thin interlayers ca n be explained with unstable cavity growth.