Multiscale simulations of low-dimensional nanomaterials: From atomic-level cracking to macroscopic network failure

Atomic-level crack propagation, interfacial delamination, as well as macroscopic network failure restrict huge applications of low-dimensional nanomaterials. It is significant from a fundamental standpoint to explore how mechanical properties of low-dimensional nanomaterials are influenced by these failures. In this review, recent progresses of the state-of-the-art experiments on failure behaviors of low-dimensional materials and their assemblies were summarized. Based on these experimental results, particular attention was paid to multiscale simulations revealing the microstructure failure mechanism hidden in experiments. First, various simulation methods, such as density functional theory, molecular dynamics simulation, as well as some continuum-based methods like atomic finite element simulation and peridynamics theory, for analyzing fractures of atomic-level monolayer low-dimensional nanomaterials were introduced. In addition, the modulation of fracture behaviors of these nanomaterials by defects was also discussed. Second, the interfacial strength and interfacial debonding of low-dimensional nanomaterials by theoretical models and simulations were described. Different interfacial optimization strategies for weakening or enhancing interfacial adhesion were addressed. Finally, various failure modes of these nanomaterial assemblies were addressed, in which the roles of internal factors and external factors were highlighted. This review will be useful for understanding the mechanism behind their failures and providing insight into atomic cracking, interfacial fracture, and macroscopic failure of van der Waals heterostructures.