Determination of strain rate dependent material data for FEA crash simulation of polymers using digital image correlation

Abstract

The measurement of the temporal and local true strain behavior of polymer materials is important for the advancement in the sector of crash simulation of plastics parts. To simulate the strain rate dependent plastic material behavior of polymers under impact conditions using FEA (Finite Element Analysis), true stress/strain-curves at different constant strain rates are required as input data. A new approach for the measurement of true stress/strain-curves at constant strain rates is presented in this paper. The approach is based on a time based correlation method and works completely without using FEA based optimization procedures like inverse analysis. It only uses data measured in mechanical testing to almost automatically generate true stress/strain-curves at different constant strain rates.