Stability Conditions in Quasi-Static Crack Propagation for Constant Strain Energy Release Rate

Abstract

Measurement of valid fracture toughness of engineering materials and design assurance of quasi-static crack growth in structures before the onset of fracture instability are the important factors in the study of fracture mechanics. Generalized equations of the stability conditions are presented not only for linear but also for nonlinear load-displacement relationships at constant crack area. Examples are used to illustrate the applications of the proposed equations, and stability conditions of different crack geometries and loadings commonly observed in engineering structures are discussed. Experiments conducted to verify the stability conditions are described and found to be satisfactory.