A Flash X-Ray Technique to Measure Strain Distribution at Interfaces Sliding at High Pressure and Velocity

Abstract

In this technique blocks of metal of widely different densities are placed in contact to form a composite block. Detonating an explosive charge positioned on the edge of the assembly drives the light metal at a higher velocity than the heavy metal resulting in sliding between the metal blocks. The aim is to measure the strain distribution in the material adjacent to the sliding interface by radiographing thin foils embedded in both materials perpendicular to the interface. A high density foil is inserted in the low density material and a low density foil in the high density material. Use of a high energy flash x‐ray machine allows large metal blocks to be used which in turn allows radiographs to be taken at a time when significant slip has occurred. The foil fiducials were clearly seen in a pilot experiment fired with aluminium and steel blocks. The result of this experiment was well matched by a hydrocode. The code has been used to design an experiment to provide data on sub surface deformation.