The interference response of reflected transient waves from several micro plane cracks

Abstract

On the concave mirror which has the curvature of the paraboloid, the plane transient wave impinging to the mirror perpendicularly is reflected and wave energy is collected in one focus. Therefore, it is widely used as a mirror for kindling a torch in the Olympics and a parabolic antenna for the radio wave reception. This phenomenon can be easily explained by the ray theory and it can be freely applied for the steady incidence and transient incidence of the wave. But, when not only the concentration point of the wave energy but also the interference response of the reflected waves which spreads in various directions from the specific boundary are examined, the exact analysis of the reflection response is required and it can not be easily grasped. If the position of an energy-minimum point by the complicated interference of reflected transient waves is detected, it becomes engineeringly a very important knowledge from the viewpoint of the material protection. In this study, the interference response of SH reflected transient waves made by the reflection system composed of several micro plane cracks is examined with the exact analysis, and the numerical results are shown using 3-D graphic representations. © 2006 Soc. Mater. Eng. Resour. Japan.