摘要
运用细观力学中的均匀化方法分析了韧性复合材料的塑性极限承载能力.从反映复合材料细观结构的代表性胞元入手,将均匀化理论运用到塑性极限分析中,计算由理想刚塑性、Mises组分材料构成的复合材料的极限承载能力.运用机动极限方法和有限元技术,最终将上述问题归结为求解一组带等式约束的非线性数学规划问题,并采用一种无搜索直接迭代算法求解.为复合材料的强度分析提供了一个有效手段.
This paper is to determine the bearing capacities of ductile composites by means of the homogenization theory of micromechanics and the plastic limit analysis. To reflect the microstructures of a composite, a representative volume element (RVE) is first selected. According to the homogenization theory, the overall fields are decomposed into macroscopic average and microscopic fluctuation terms, which can reflect the relation between macroscopic and microscopic scales. Then, by introducing the homogenization theory into the plastic limit analysis, a strategy for the direct computation of the limit load of a microstructure RVE is put forward. For such ductile composites as metal matrix composites (MMC), the constitutions is assumed as rigid-perfectly plastic solids and obey the von Mises yield criterion. By means of the kinematic limit approach and finite element method, the numerical modeling of the plastic limit analysis of a composite is formulated as a nonlinear mathematical programming with equality-constraint conditions, which can be solved by a direct iterative algorithm developed. Numerical examples show the validity of the method and the high effectivity of the algorithm. It can be concluded from numerical results that the macroscopic strength of a composite is mainly determined by weak constitutions in the plane model and that the reinforced effects of fibers are most intensive in the off-axis direction. The method presents an effective tool for the strength analysis of ductile composites.
出处
《力学学报》
EI
CSCD
北大核心
2002年第4期550-558,共9页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金(19902007)
全国优秀博士论文基金(200025)
教育部留学回国人员启动基金
清华大学机械学院基础研究基金资助项目
关键词
韧性复合材料
均匀化理论
塑性极限
细观力学
composite, homogenization theory, plastic limit, representative volume element (RVE), kinematic limit
