Influence of geometry and material on the stress intensity of an interfacial crack propagating from a bi-material notch

Abstract

The stress intensity factor (SIF) is an important parameter to characterize the stress intensity near a crack tip. In order to successfully evaluate the SIFs for the interfacial crack emanating from a bi-material notch, a method coupling the boundary element method with the singularity asymptotic expansion technique is introduced. Then, the crack initiating from a sharp V-notch tip and the one emanating from a semicircle notch root are respectively taken into consideration, to investigate the influence of notch geometry shape and material property on the stress intensity for the interfacial crack from a bi-material notch. It is found that the notch opening angle has great influence on the SIFs of an interfacial short crack, while it has little influence on the SIFs of an interfacial long crack propagating from a bi-material V-notch. The value of KI for the interfacial crack initiating from a V-notch tip increases with the notch depth, while KII decreases with it. The value of KI and absolute value of KII for the interfacial crack initiating from a V-notch tip increase with the elasticity modulus ratio. The elasticity modulus ratio has little influence on KI, while it has important influence on KII for the interfacial crack emanating from a semicircle notch root. The value of KI and absolute value of KII for the interfacial crack initiating from a semicircle notch root increase with the notch radius.