TDBEM analysis of microbranching in dynamic Crack Growth

Abstract

A principle of maximum energy dissipation rate has been proposed for microbranching in dynamic crack growth. During dynamic growth, cracks propagate in such configurations, as to lead maximum energy dissipation per unit of time. A model for 2D dynamic crack microbranching is presented by employing time‐domain dual boundary element method (TDBEM). In this model, the objective function is the negative sum of the length of crack growth in each time step, and constraint conditions are that dynamic stress intensity factors (DSIFs) of all growing cracks reach a critical value. Sequential quadratic programming is adopted to solve this optimization problem. In order to reduce the error of numerical integration and keep the system stabler, a special method is developed to deal with the weakly singular integration in TDBEM. The comparison of computational and experimental results shows that the principle of maximum energy dissipation rate in crack microbranching is reasonable to interpret some phenomena of dynamic crack growth in brittle materials.