Crack Propagation and Debonding Study of Thin Films on Compliant Substrates Based on a Novel Nonlocal Damage and Cohesive Zone Model

Abstract

Precise modeling of brittle materials is essential for guaranteeing their reliable performance in practical applications. In this study, a new nonlocal macro-meso-scale consistent damage (NMMD) model coupled with the cohesive zone model is exploited to simulate the fracture behavior of thin films deposited on compliant substrates. The NMMD model provides an efficient and physically consistent framework for capturing fracture evolution in brittle thin-film–substrate structures. This model, unlike the phase-field method, avoids solving an auxiliary or additional phase-field evolution equation, which significantly reduces the computational cost and total degrees of freedom while maintaining high predictive accuracy. Besides, the NMMD model captures damage evolution through nonlocal internal variables while preserving energy balance across scales. By precisely tuning the interfacial fracture toughness, the NMMD model quantitatively tracks crack trajectories and interfacial delamination zones, revealing the critical dependence of brittle fracture regimes on interfacial toughness parameters. Furthermore, the model systematically deciphers how interfacial fracture toughness governs crack propagation dynamics within the NMMD framework, bridging microscale mechanics to macroscale failure predictions.