Characterization of the Dynamic Strain Hardening Behavior from Full-field Measurements

The purpose of the present study is to provide a procedure for identifying dynamic strain hardening parameters using an inverse method to determine more accurate hardening properties at high strain rates for automotive crash analysis simulations. In order to validate the procedure, an approprate elasto-plastic constitutive model was chosen and simulated measurements were retrieved using a finite element (FE) analysis program. The same identification procedure as that which will be implemented in the experiments was applied. The virtual fields method (VFM) was used as an inverse analytical tool to identify the constitutive parameters. Because accurate measurement of the applied load is not easy at high strain rates due to the inertial effect, the identification was conducted using the acceleration fields without utilizing load information. The identified parameters using the VFM were compared with the reference ones, which were fed into the FE simulations. Very promising results were acquired using the VFM.