A Hybrid Experimental-Numerical Converse Method for the Necking Behavior Study of High Strength Steel Sheets

To characterize the plastic behavior of a dual phase (DP) steel, tension tests under four different strain rates were conducted. The results show that necking phenomenon exists in all the tests. To solve the unreliability problem of the conventional data processing method brought by the 3D stress state of the necking behavior, a hybrid experimental-numerical converse method was employed. The onset of necking phenomenon was determined firstly according to the test results and the hardening curve was extrapolated from the necking onset following the Ludwik hardening law. Then, the extrapolated curve was optimized to achieve a good agreement between simulation and experimental results. At last, this method was applied to the studied DP steel, and the hardening curves for the characterization of tension tests were obtained.