Analysis of the Bimaterial Interface Cracks Based on Configurational Forces

Abstract

In this paper, an innovative interface fracture criterion is proposed based on the concept of configurational forces in material space. In this criterion, the crack-tip configurational forces as the driving force are introduced to describe the interface crack evolution under mixed-mode loading conditions. And it assumes that the interface crack propagates due to the competition of resultant configurational forces with interface fracture toughness. The analytical expression of the configurational forces is obtained by differentiating the elastic strain energy density and conservative integral for interface cracks. And the relation of interface crack-tip configurational forces with classical complex intensity factors is obtained through strict mathematical deduction. The interface crack-tip configurational forces are evaluated for a classic interface crack problem covering a wide range of bimaterial oscillation indexes. The configurational forces-based interface fracture criterion is validated through series interface fracture experiments. The proposed criterion may provide a novel framework for the analysis of interface fracture under complex loading conditions.