Parameter identification for improved viscoplastic model considering dynamic recrystallization

The successful application of viscoplastic model considering dynamic recrystallization depends on how well the parameters are identified. However, it is difficult to obtain satisfactory parameters using conventional parameter identification methods. The reasons are due to difficulties in obtaining homogeneous deformation, high complexity of physical process described by the model and large number of parameters. In this paper, the material parameters are identified by inverse analysis. Global information on objective function is firstly studied by an improved uniform random sampling method; secondly, a hybrid global optimization method, which combines the genetic algorithm, the Levenberg-Marquardt algorithm, the augmented Gauss-Newton algorithm and the flexible tolerance method, is constructed and an inverse analysis numerical procedure, which combines the proposed optimization method with the finite element analysis, is proposed; at last, a set of satisfactory material parameters for 26Cr2Ni4MoV is obtained by the proposed inverse analysis numerical procedure. (c) 2004 Elsevier Ltd. All rights reserved.