With the guidance of Prof. Li，the work titled “Bifurcation criterion and the origin of limit crack velocity in dynamic brittle fracture” studied by doctor Fucheng Tian et al. has been published in International Journal of fracture.
Understanding the mechanism of crack dynamics in the brittle fracture is still an ongoing challenge in solid-state physics and material science. Among the diverse unresolved problems in dynamic brittle fracture, the criterion for crack bifurcation and the origin for limit crack propagation velocity are two important issues. By employing computer simulations based on a variational phase model, this contribution aims to reveal the branching criterion in brittle fracture and clarify the origin the limit crack velocity. Without any a priori assumption, the crack patterns and velocity evolutions analogous to those observed in the experiments are reproduced perfectly, as shown in the following picture. Our results demonstrate that crack bifurcation obeys a universal energy criterion in brittle materials. By considering the energy criterion, the long-standing issue of limit crack propagation velocity can be favorably clarified by the continuum theory of LEFM, indicating that it stems from the crack bifurcation. Combining our phase field simulation and classical LEFM, the path selection of cracks in the brittle fracture can be rationally explained.
This work is supported by the National Natural Science Foundation of China (51633009, 51890872).
Related links: https://link.springer.com/article/10.1007/s10704-020-00449-z
