MECHANICAL-BEHAVIOR OF A DUCTILE POLYAMIDE-12 DURING IMPACT

The mechanical behavior of a polyamide 12 is characterized using a vis coplastlc law taking into account viscoelastic deformation. Experiment al determinations are performed at constant and very low strain-rates in isothermal conditions during tensile tests. A finite elements code, based on this behavior, enables us to reproduce tensile tests even at different strain rates (up to 0.5 s(-1)) provided that heat power dis sipation due to deformation is taken into account. The same model part ially reproduces multiaxial impact tests. Strain hardening is generall y over-estimated by the calculation. It is pointed out that mechanical behavior should be characterized in ways closer to impact loading con ditions than tensile tests to be more efficient because of the differe nce in microstructural evolutions during drawing.