Dynamic compression-shear loading with in-material interferometric measurements

The present article introduces a new technique for window interferometry in the case of combined normal and shear wave motion. The method can, in principle, be used for micromechanical studies of damage and inelasticity in a variety of materials. Preliminary tests conducted on brittle materials indicate the feasibility of the technique and its advantages over other in-material measurements using embedded manganin gauges or electromagnetic particle velocity gauges. An analysis of the interferometric signals, incorporating variations in the index of refraction of the window material, is used in the interpretation of the velocity histories. The suitability of the technique in the study of dynamic failure and material instabilities is presented. Furthermore, the use of the in-material measurement technique in the design of pressure-shear recovery experiments is described. (C) 1996 American Institute of Physics.