Transient Stress Wave Boundary Interactions

Abstract

Impulsive loads such as are produced by explosions and impacts, on introducing transient stresses into the materials against which they act, start a series of events. At first, fractures and highly localized internal stresses may develop ; later, rod, plate, Love, Rayleigh, and other similar waves may appear. The character of these transitory and evolutionary processes is controlled in a large measure by the interactions which take place both among the transient stress waves themselves and between the stress waves and the boundaries or interfaces which they encounter. These interactions can exert a strong attenuating effect on a wave by disorganizing it and splitting its energy up into diverse modes. The attainment of a full appreciation of the attenuation processes requires a complete understanding of the nature of the interactions themselves, an understanding which may be hampered by the fact that the interaction processes are quite complicated, difficult, and extremely tedious to treat in a rigorous manner. However, some of the more important interactions are amenable to relatively simple treatment. The purpose of this paper is to describe a few interactions that have not heretofore been discussed and to present some new experimental data bearing on them.

Work supported in part by the National Science Foundation and in part by the Office of Naval Research.