THE EFFECT OF INERTIA ON TENSILE DUCTILITY

One-dimensional numerical simulations of dynamic tensile tests have be en carried out over a wide range of test velocities for materials havi ng a Hollomon-type constitutive law with power-law strain-rate sensiti vity. A variety of values of the strain-hardening exponent and strain- rate-sensitivity index have been used to analyze the effect of inertia on tensile ductility. Results show that the total elongation of the s pecimen is enhanced by inertia at high test velocities. This inertial effect varies with the strain-hardening exponent and strain-rate-sensi tivity index and can be scaled with the normalized material density an d the test velocity. Based on these results, the critical test velocit y for the onset of the inertial effect as a function of material param eters has been numerically determined. To account for the effect of in ertia on the enhancement of tensile ductility, a simple phenomenologic al explanation has been proposed.