Experimental investigation and crystal plasticity–based prediction of AA1050 sheet formability

Abstract

This article presents a crystal plasticity methodology to evaluate the AA1050 sheet formability. In order to determine the orientation distribution of the crystals, initial texture of the material is measured through X-ray diffraction technique. Also, the stress–strain behavior of the material is determined by performing tensile test. In order to simulate the path-dependent crystal plasticity behavior of body-centered cubic crystal structures, a UMAT subroutine that employs the rate-dependent crystal plasticity model along with the power law hardening was developed previously by the authors and linked to the finite element software ABAQUS. This subroutine was further developed to simulate face-centered cubic crystal structures. The second-order derivative of sheet thickness variations with respect to time is considered as the instability factor, and forming limit diagram of the material is predicted. In order to assess the validity of formability prediction results for face-centered cubic materials, forming limit diagram of AA1050 sheet is also experimentally extracted by conducting hemi-spherical punch test. It is observed that the predicted forming limit diagram is in agreement with the experimental results. Finally, the prediction accuracy in different regions of forming limit diagram is discussed and some suggestions for further improving the accuracy are made.

A Review of Characterization and Modelling Approaches for Sheet Metal Forming of Lightweight Metallic Materials

“…Besides, they introduced a novel technique to predict the localization onset via simulating the RVEs for two material points only. Hajian et al [ 434 , 435 ] combined the M–K model with their new 2D-CPFE model. They assumed initial imperfections oriented along different directions and simulated the forming limits criterion.…”

“…They assumed initial imperfections oriented along different directions and simulated the forming limits criterion. The above-mentioned models [ 429 , 432 , 433 , 434 , 435 ] could not precisely solve the issue of heterogeneity of stresses and strains in the thickness direction. Thus, researchers proposed the 3D-CPFE model with multi-grains in the thickness direction and introduced multiscale frameworks-based CP modelling to predict FLDs accurately.…”