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Theoretical Development of Optimization Problem of Material Composition and Evaluation of Thermal Stress Intensity Factor for Heat-Resisting Functionally Graded Materials

耐热功能梯度材料材料成分优化问题及热应力强度因子评估的理论发展

基本信息

批准号：
06650115
负责人：
TANIGAWA Yoshinobu
金额：
$ 1.22万
依托单位：
University of Osaka Prefecture
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

In this research project, thermal stress problems for nonhomogeneous materials such as the Functionally Graded Materials are treated theoretically for several analytical models. The FGMs are composed of the light metals and the engineering ceramics, and now attracts our engineering attention by the effect of thermally induced stress relaxation. Then, the following two practical problems are dealt with theoretically in the present research project.1. Optimization problems of material composition for nonhomogeneous body to minimize thermal stresses under the condition of unsteady heatingIn this research, taking into account the several analytical model, such as a plate, a cylindrical shell and spherical shell composed of nonhomogeneous materials, the optimization problems of material composition to minimize the transient thermal stress distributions are treated theoretically. And the optimum material composition are determined from the nonlinear programming method of calculations. And th … More e variations of several numerical parameter, such as temperature-dependency of material properities, temperature rise, thickness and the conditions of heat transfer, affected to the optimum material composition are examined from the numerical data of calculation.2. Evaluation of thermal stress intensity factor for nonhomogeneous bodyIn this research, theoretical development of thermal stress intensity factor for nonhomogeneous body is treated theoretically. As an analytical model, Kassir' s nonhomogeneous infinite body with a pennyshaped crack is considered. Assuming that the body is subjected to uniform heat flox from the crack surface, and the material properties such as thermal conductivity, shear modulus of elasticity and coefficient of linear thermal expansions vary with the axial direction according to the relation of power product form of the coordinate variable, the thermal stress intensity factor is evaluated theoretically. And the effects of variation of these material properities to the stress intensity factor are examined from the numerical data. Less

在本研究项目中，对功能梯度材料等非均质材料的热应力问题进行了理论分析。fgm是由轻金属和工程陶瓷组成，由于其热致应力松弛效应而引起工程领域的广泛关注。然后，在本研究项目中对以下两个实际问题进行了理论处理。非均匀体非定常加热条件下材料成分优化问题考虑非均匀材料组成的板、柱壳和球壳等几种分析模型，从理论上研究了材料成分优化问题，以使瞬态热应力分布最小化。并采用非线性规划计算方法确定了最优材料组成。并从数值计算数据中考察了材料性能的温度依赖性、温升、厚度和传热条件等数值参数的变化对最优材料组成的影响。非均匀体热应力强度因子的计算从理论上处理了非均匀体热应力强度因子的理论发展。作为一种解析模型，考虑了带便士形裂纹的Kassir非齐次无限体。假设物体受到来自裂纹表面的均匀热流，并且材料的导热系数、剪切弹性模量和线性热膨胀系数等性能根据坐标变量的幂乘积形式的关系沿轴向变化，从理论上计算热应力强度因子。并从数值数据上考察了这些材料性能的变化对应力强度因子的影响。少