Analyze the influence of explosion stress wave on the dynamic fracture of PMMA plates with different curvature radius defects

Defects in brittle solid materials affect the transmission of stress waves, thereby influencing the fracture process of the material. In this paper, the effect of defect curvature radius on the propagation of explosion stress wave and crack propagation is studied. Polymethyl methacrylate (PMMA) is used as the experimental material. The explosive loading and transmission caustics systems are combined to observe and record the explosive fracture process of a PMMA plate with different curvature radius defects. First, the interaction process between the explosion stress wave and defects with different radii of curvature is analyzed via caustics. Then the propagation process of prefabricated defects under the action of the explosion stress wave is studied. Moreover, crack tip propagation speed and the change of the stress intensity factor are simultaneously calculated. Numerical simulation is used to restore the full-field stress change under the action of the explosion stress wave and the defect. Lastly, stress time history curve of the point in the proximity of the defect is analyzed.