Non-oscillatory fracture mode partition for interface crack under mixed-mode loading

•A series solution for an interface crack under remote mixed-moded loading is given.•Fracture mode mixity based on the non-oscillatory cohesive-spring interface solution is presented.•Machine-learning model was developed for fast evaluation of phase angle.•Can be applied to interface fracture characterization for IC interconnect structure. The oscillatory crack-tip field in the classical interface fracture mechanics solution often leads to complications in identifying the mode mixity in bimaterial interface fracture problems. In this paper, a non-singular series solution for the continuum problem of a crack on the cohesive-spring interface under mixed-mode loading is presented and compared to the classical oscillatory solution. A Gaussian process regression model was also developed to enable quick evaluation of the phase angle for interface delamination characterization by using mixed-mode bending fracture test.