Stress Intensity Factor Analysis of an Interface Crack between Anisotropic Dissimilar Materials under Thermal Stress

点击翻译按钮获取中文摘要

The stress intensity factors of an interface crack between dissimilar materials are important parameters for the evaluation of the integrity of electronic devices, adhesive structures and composite materials. We must use a numerical technique like the finite element method to analyze the stress intensity factors of an interface crack in an actual structure. In this study, we developed a numerical technique to analyze stress intensity factors of an interface crack between dissimilar materials under thermal stress. Final object of this study is to develop the anisotropic version of this method and the application to the evaluation of the reliability of electronic devices. We carried out several works as follows.(1) We modified the virtual crack extension method and the crack closure integral method for an interface crack between dissimilar materials under thermal stress condition. We demonstrated that the both methods is one of the most accurate methods to calculate the stress intensity factors of an interface crack.(2) The direction of the kinking of an interface crack can be predicted using the maximum hoop stress criterion that is derived from stress intensity factors of an interface crack.(3) We applied the stress intensity factors of an interface crack to evaluate the delamination between dissimilar materials used in semiconductor chips.(4) We developed a computer code to calculate the asymptotic solution of the stress distribution around an interface crack between dissimilar anisotropic materials using the Stroll formalism. This is the most important step to develop the numerical technique to calculate stress intensity factors of an interface crack between anisotropic dissimilar materials. We also derived the analytical solution of the stress intensity factors of a center interface crack between jointed semi-infinite anisotropic plates under uniform tension and shear.