| Popis: |
Dynamic failure in advanced ceramic materials is a complex mechanical phenomenon, which is challenging to study in experimental and computational works. This work models and investigates the crack initiation, growth, propagation, and branching in two-dimensional single crystalline boron carbide at the nanometer length-scale and picosecond time-scale. A phase-field approach is used by carefully selecting the interfacial energy allowing a monolithic numerical solution method capturing strong coupling between mechanics and damage. Specifically, the transient Ginzburg–Landau equation is coupled with the balance of momentum including geometric nonlinearities and solved by using the open-source computing platform FEniCS. The monolithic computation ensures necessary accuracy for dynamic fracture under pure mode I loading, and also demonstrates the capability of crack branching depending on the loading rate. The effect of crack regularization length and kinetic coefficient on the crack interface profile and crack tip velocity is also studied. Altogether, the results are important for modeling anisotropic fracture in advanced ceramics and designing materials with desired dynamic failure characteristics. |
