An experimental and theoretical investigation of high strain rate tension tests and the search for a general model explaining the observed behavior

Dynamic tensile tests, at speeds ranging between 10 and 50 ms-1, were carried out on two materials of different crystalline structure, in order to find a function characteristic of their plasticities and to establish whether the behavior equation used is the general equation and consistent with dynamical behavior. The work is divided into three chapters. The first chapter deals with generalities about deformation at high strain rates, together with the principal measuring methods. The second chapter presents a theoretical model based on dislocation theory which explains the behavior of a 17 per cent chromium enriched ferritic steel subjected to a high strain rate tension test. The third chapter deals experimental work carried out on pure crystalline Cu. Three stages were observed during the macroscopic deformation of the sample and a hypothesis was put forward relating them to microscopic mechanisms observed with transmission electron microscopy. (author)