A BEHAVIOR OF STRESS WAVES IN PMMA WITH A STEP

摘要

Visualization studies were performed both experimentally and theoretically to observe stress wave propagation in a material and its interaction with the stepped free surface of the material in a blasting process. PMMA (polymethyl-methacrylate) plates were used as a transparent material. The stress wave was generated by initiation of an electric detonator. The stress waves in the PMMA specimen and shock waves in air were observed by means of the laser-shadowgraph method. In addition to the experiment, we analyzed the dynamics of stress wave interacting with the stepped free surface using the smoothed particle hydrodynamics (SPH) method. The results obtained from the numerical calculation were compared with experimental results of the model blasting. Propagation of stress waves, reflection and transmittance at the interface between PMMA and air were visualized both experimentally and numerically.