Fracture Energy of Materials Exposed to Pulse Action

To study the process of brittle fracture, initiated by a microsecond range pulse action, we applied the magnetic pulse technique of controllable pressure pulse generation with pulse amplitude up to 2 GPa. The threshold energy level has been found, and related to a parameter specific of each material - energy accumulation time. With application of the thermodynamic approach, we develop and demonstrate the destruction criterion that allows us to define this material parameter. Following the results of experimental data and numerical simulation, we show how to describe the destruction process both for samples with crack-type macro defects, and defect-free samples. The study reveals the dependency of the surface energy from the load build-up and material properties when exposed to magnetic pulse action.