Material Modeling of 6000 Series Aluminum Alloy Sheets with Different Density Cube Textures and Effect on the Accuracy of Finite Element Simulation

Abstract

Biaxial tensile tests of 6000 series aluminum alloy sheet with different density cube textures were carried out using cruciform specimens similar to that developed by one of the authors [Kuwabara, T. et al., J. Material Process. Technol., 80/81(1998), 517–523.]. The specimens are loaded under linear stress paths in a servo‐controlled biaxial tensile testing machine. Plastic orthotropy remained coaxial with the principal stresses throughout every experiment. Successive contours of plastic work in stress space and the directions of plastic strain rates were precisely measured and compared with those calculated using selected yield functions. The Yld2000‐2d yield functions with exponents of 12 and 6 [Barlat, F. et al., Int. J. Plasticity 19 (2003), 1297–1319] are capable of reproducing the general trends of the work contours and the directions of plastic strain rates observed for test materials with high and low cube textures, respectively. Hydraulic bulge tests were also conducted and the variation of thickness strain along the meridian direction of the bulged specimen was compared with that calculated using finite element analysis (FEA) based on the Yld2000‐2d yield functions with exponents of 12 and 6. The differences of cube texture cause significant differences in the strain distributions of the bulged specimens, and the FEA results calculated using the Yld2000‐2d yield functions show good agreement with the measurement results.