Finite Element Modeling of Springback Behavior for Aluminum 6000 Series Sheets Using Three-Point Bending Tests

Abstract

The springback behavior of aluminum alloy (AA) 6061-T6 sheets during three-point bending was investigated through experimental and numerical methods. Finite element (FE) simulations were conducted using advanced material models, including the Yld2000-2d yield criterion, a Chaboche-type nonlinear kinematic hardening model, and a model for elastic modulus degradation, to improve prediction accuracy. Mechanical properties were characterized through uniaxial tension and compression-tension tests, capturing critical behaviors such as the Bauschinger effect, transient hardening, and permanent softening. The FE simulations demonstrated strong agreement with experimental results, accurately predicting load-displacement and springback behavior for as-received and pre-strained samples. The isotropic hardening model over-estimated springback due to its inability to account for anisotropic hardening effects. In contrast, the Chaboche model successfully captured the anisotropic hardening and elastic recovery, leading to precise springback predictions. The findings underscore the importance of incorporating advanced material modeling approaches to enhance the accuracy of springback predictions in sheet metal forming. This study provides valuable insights for the design and manufacturing of lightweight and dimensionally accurate components, particularly in the automotive and aerospace industries.