Metamodel-based inverse method for parameter identification: elastic–plastic damage model

This article proposed a metamodel-based inverse method for material parameter identification and applies it to elastic–plastic damage model parameter identification. An elastic–plastic damage model is presented and implemented in numerical simulation. The metamodel-based inverse method is proposed in order to overcome the disadvantage in computational cost of the inverse method. In the metamodel-based inverse method, a Kriging metamodel is constructed based on the experimental design in order to model the relationship between material parameters and the objective function values in the inverse problem, and then the optimization procedure is executed by the use of a metamodel. The applications of the presented material model and proposed parameter identification method in the standard A 2017-T4 tensile test prove that the presented elastic–plastic damage model is adequate to describe the material's mechanical behaviour and that the proposed metamodel-based inverse method not only enhances the efficiency of parameter identification but also gives reliable results.     

差分演化的收敛性分析与算法改进

为了分析差分演化(differential evolution,简称DE)的收敛性并改善其算法性能,首先将差分算子 (differential operator,简称DO)定义为解空间到解空间的笛卡尔积的一种随机映射,利用随机泛函理论中的随机压缩 映射原理证明了DE 的渐近收敛性;然后,在“拟物拟人算法”的启发下,通过对DE 各进化模式的共性特征与性能差 异的分析,提出了一种具有多进化模式协作的差分演化算法(differential evolution with multi-strategy cooperatingevolution,简称MEDE),分析了它所具有的隐含特性,并在多模式差分算子(multi-strategy differential operator,简称 MDO)定义的基础上证明了它的渐进收敛性.对5 个经典测试函数的仿真计算结果表明,与原始的DE,DEfirDE 和 DEfirSPX 等算法相比,MEDE 算法在求解质量、适应性和鲁棒性方面均具有较明显的优势,非常适于求解复杂高维 函数的数值最优化问题.