A rate-dependent cohesive model for simulating dynamic crack propagation in brittle materials |
| |
Authors: | Fenghua Zhou Tadashi Shioya |
| |
Affiliation: | a Department of Mechanical Engineering, Johns Hopkins University, 232 Latrobe Hall, 3400 N. Charles Street, Baltimore, Maryland 21218, USA b Department of Aeronautics and Astronautics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan |
| |
Abstract: | Numerical investigations are conducted to simulate high-speed crack propagation in pre-strained PMMA plates. In the simulations, the dynamic material separation is explicitly modeled by cohesive elements incorporating an initially rigid, linear-decaying cohesive law. Initial attempts using a rate-independent cohesive law failed to reproduce available experimental results as numerical crack velocities consistently overestimate experimental observations. As proof of concept, a phenomenological rate-dependent cohesive law, which bases itself on the physics of microcracking, is introduced to modulate the cohesive law with the macroscopic crack velocity. We then generalize this phenomenological approach by establishing a rate-dependent cohesive law, which relates the traction to the effective displacement and rate of change of effective displacement. It is shown that this new model produces numerical results in good agreement with experimental data. The analysis demonstrates that the simulation of high-speed crack propagation in brittle structures necessitates the use of rate-dependent cohesive models, which account for the complicated rate-process of dynamic fracture at the propagating crack tip. |
| |
Keywords: | Dynamic crack propagation PMMA Velocity-toughening Numerical simulation Cohesive element Rate-dependent cohesive law |
本文献已被 ScienceDirect 等数据库收录! |
|