Simulation Effect of Twinning Evolution on Metal Strength under Dynamic Loading

The dynamic response materials under shock wave loading and complex deformation conditions are significantly different from those of low pressure and low strain rate loading. The experimental results show that the plastic deformation mechanism has changed. For lower fault energy materials (such as Ta, Be, etc.), twinning are another important mechanism of plastic deformation. In this paper, the twinning process is modeled and added into the thermo-viscoplastic crystal plasticity. The evolution of twin in Ta and Be materials during impact loading and unloading is studied by numerical simulation. The change in the strength of the material with the twins was analyzed. The results show that the effect of twinning on the mechanical strength of Ta and Be is not the same under medium and high strain rate loading. Twins are more sensitive to the strength and texture evolution of Be. Twin is an important physical mechanism of plastic deformation to Be under the shock wave loading.