Construction of a Multi-System of Structural Design of Configuration and Material Composition for Functionally Inhomogeneous Materials : Optimization Problem of Structural Element Making Use of Genetic Algorithm and Cellular Automata

本课题主要研究功能非均质材料的材料组成和结构单元构型的优化问题。作为解析模型，考虑了在任意非均匀热源作用下的空心球体和空心圆柱。假设非均匀材料的导热系数、弹性常数和热膨胀系数在厚度（径向）和周向上都是任意变化的。进一步，将空心球视为轴对称二维问题。另一方面，将空心圆柱体处理为非对称平面应变状态。对于这些分析模型，首先考虑的是材料成分的优化问题。假设这些功能非均质材料在超高温环境下使用，则将热应力松弛和耐热性作为优化问题的目标函数。由于材料的性质在考虑的范围内是任意变化的，因此几乎不可能得到温度和相关热弹性场的解析解。因此，利用有限元法对温度场和热弹性场进行了分析。然后，利用遗传算法对材料组成进行多目标优化。得到了空心球体和空心圆柱体等功能非均质固体材料组成的pareto最优解。其次，考虑了结构单元的构型优化问题。对于这类优化问题，选择在保持强度约束下的减重作为目标函数。利用有限元法和遗传算法、元胞自动机等软计算系统进行了分析。该系统目前正在建设中，因此，还不能得到数值结果，但它将在不久的将来发表。少

In this research project, the optimization problems of the material composition and the configuration of structural elements for functionally inhomogeneous materials are treated. As analytical models, a hollow sphere and a hollow circular cylinder subjected to an arbitrary nonuniform heat supply are considered. It is assumed that the inhomogeneous material properties such as the thermal conductivity, elastic constants and the coefficient of thermal expansion are varied arbitrarily in both the thickness (radial) and circumferential directions. Furthermore, the hollow sphere is treated as axisymmetric two-dimensional problem. On the other side, the hollow cylinder is treated as nonsymmetrical plane strain state. For these analytical models, the optimization problems of the material composition are considered as a first step. Supposing that these functionally inhomogeneous materials are used in the super-high temperature environment, both the thermal stress relaxation and the heat resista … More nce are taken into account as objective functions for the optimization problem. The development of the analytical solution for the temperature and the associated thermoelastic fields are almost impossible because the material properties are changed arbitrarily in the domain under consideration. So that, the analyses for the temperature and the thermoelastic fields are carried out making use of the Finite Element Method. Thereafter, the multi-objective optimizations for the material composition are treated with aid of the Genetic Algorithm.The Pareto-optimal solutions of the material composition for functionally inhomogeneous solids such as a hollow sphere and a hollow cylinder are obtained. Secondary, the optimization problems for the configuration of the structural element are taken into consideration. For such optimization problems, the reduction of the weight under the restriction of the maintenance of the strength is selected as an objective function. The analyses are also developed making use of Finite Element Method and the soft-computing systems such as Genetic Algorithm and Cellular Automata. The systems are now under constructing, so that, the numerical results could not be obtained yet, but it will be published in the near future. Less