The inverse parameter identification of Hill 48 yield criterion and its verification in press bending and roll forming process simulations

Yield criterion is an essential factor that affects the FEM simulation accuracy. In order to improve the simulation accuracy of bending processes including press bending and roll forming which are mainly under plane strain condition, an inverse parameter identification method to determine the parameters of Hill 48 yield criterion in a convenient manner is presented. The plane strain tensile test is performed, and the orthogonal experiments based on FEM simulations are conducted. Then the parameters of Hill 48 yield criterion are obtained based on the load-displacement data of both the test and simulation results. Press bending and roll forming processes are selected to verify this parameter identification method. Final shapes of the experimental and numerical results are compared. It is shown that the numerical results based on Hill 48 yield criterion are better than those based on Mises yield criterion in terms of the final shapes, which indicates that the proposed method is reliable and can well reflect material behavior in real forming processes. (C) 2015 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.