2020 Volume 106 Issue 9 Pages 630-639
The elastic-plastic deformation behavior of a 440 MPa hot-rolled steel sheet subjected to many linear stress paths is precisely measured using biaxial tensile tests with cruciform specimens (ISO 16842: 2014) and multiaxial tube expansion tests (Kuwabara and Sugawara, 2013) to determine appropriate material models for finite element analysis (FEA). It was found that the Yld2000-2d yield function (Barlat et al., 2003) correctly reproduces the contours of plastic work (CPW) and the directions of the plastic strain rates (DPSR). Differential hardening (DH) models are determined by changing the values of exponent and material parameters of the Yld2000-2d yield function as functions of reference plastic strain. Moreover, FEA of the hole expansion forming of the test material is performed. The DH model correctly predicts the minimum thickness position that matches the fracture position of the specimen in experiment.
