Thick anisotropy analysis for AA7B04 aluminum plate using CPFEM and its application for springback prediction in multi-point bending

The mechanical anisotropy of AA7B04 aluminum plate in thickness direction has an impact on the springback prediction in multi-point bending. A modelling method with consideration of the texture gradient of the plate in thickness direction was proposed to predict the springback in the paper. The plate was divided into a number (one, three, and seven) of layers in the simulation. In each layer, Barlat2004-18p yield criterion calibrated by crystal plasticity finite element method (CPFEM) was used to describe the in-plane anisotropy. The polycrystalline orientations in different layers were measured by electron backscatter diffraction (EBSD). The three dimensions (3D) representative volume element (RVE) was developed by Voronoi tessellation method. Multi-point bending experiment were conducted and compared with the simulation. The springback prediction results show that, compared with the model with the mechanical isotropy, the precision of springback prediction is improved. The experimental verification shows that as the number of layers in the simulation increases, the accuracy improves.