Inverse Identification Of Material Parameters Employed In Simulation Of Sheet Metal Forming

An inverse method is proposed in this thesis for precise and fast determination of material parameters. In this inverse method, the finite element method is wisely combined with optimization technique to calculate material properties based on experimental results, which eliminates several drawbacks in traditional parameter test technique.An activity rule is creatively brought forward for the selection of measurement locations. The sample is divided into three parts, i.e. active section, inactive section and dead section. According to this rule the corresponding method for selection is proposed. Based on "Kingview" industrial software, the data processing and control system software is self-developed for realization of closed loop control in the displacement test machine.For the inverse method research, this paper proposes a truly original concept: simulated priori-information, which means using numerical simulation method to quest for priori information. This method greatly enriches the priori information on material parameters. In this paper two steps search method is creatively presented to quickly locate the position of measurement points in numerical model. Detailed procedure of the algorithm is proposed in this paper, using Levenberg-Marquardt method combined with Gauss-Newton strategy. And the corresponding software named limap (Inverse Identification of Material Parameters) is self-developed for solving such a nonlinear least square problem.