DYNAMIC TENSILE TESTS ON FERRITIC AND AUSTENITIC STEELS WITH IMPROVED TESTING AND MEASURING TECHNIQUE

For analysing dynamically loaded structures by means of the finite element method a dynamic constitutive material model is necessary to obtain reliable results. For this purpose dynamic tensile tests were performed with the fine grained steel 20 MnMoNi 5 5 (A 508 Cl. 3) and the austenitic steel X 6 CrNi 18 11 at different velocities. Smooth round bar specimens of different geometries were used. Displacement at the lower end of the specimen as well as force and strain were measured. The whole impact event taking place during dynamic tensile tests on a 33 MJ-rotating disk impact machine is simulated by means of the explicit finite element code DYNA3D. Information on the loading conditions during the test could be obtained and stress, strain respectively strain rate distribution along the gauge length were observed. Thus the measuring technique of stress and strain could be improved. Finally the dynamic stress-strain behaviour of the ferritic and austenitic steel is discussed.