金属成型材料参数的反求技术

给出了快速准确地获得材料处于弹塑性大变形状态下各向异性弹塑性本构模型参数反求方法。首次提出了筛选试验测试点的活度规则，并以此来指导试验测试点的位置的选择；提出了仿真先验信息的概念，丰富了获取材料参数先验信息的途径；混合采用Levenberg—Marquardt方法和Gauss—Newton法的优化策略，给出了材料参数反求的基本公式和关键算法。数值算例表明，反求参数的初值以及反求区间的确定对于反求结果有着重要影响，为了确保反求过程的顺利进行，必须充分了解材料模型的先验信息．并充分利用筛选试验测试点的活度规则。同时效值算例计算还表明本文方法具有很高的计算精度和计算效率。

An inverse method for material parameters in metal forming

The method for identification of parameters in anisotropic elasto-plastic constitutive models was presented in this paper. The method combined the experimental measurement, finite element simulation and optimization techniques. An activity rule was proposed for selecting measurement locations and the new concept of simulating priori information is first brought forward to give the feasible interval of initial values of identified parameters. Using the modified Levenberg-Marguardt method mixed with the optimal strategy of Gauss-Newton method the detail formulations and procedure were drawn and some key problems which influence the identification process seriously were discussed. Numerical examples show that the proper initial guessed parameters and the determination of feasible interval play an important rule in identified process. The simulating priori information and the activity rule for selecting measurement locations are essential for parameter identification. Numerical results indicate that the method possesses pretty good accuracy and high convergence rate.