中文摘要：

采用复合材料细观有限元分析方法,并借助先进循环塑性本构模型的有限元实现,对颗粒性态的随机性对SiC颗粒增强6061Al复合材料棘轮行为的影响进行了有限元数值模拟。采用随机序列吸附方法（RSA）生成各种多颗粒随机分布的模型,探讨了颗粒分布方式、数目、形状和大小以及各自的随机性对复合材料棘轮行为的影响。研究发现：颗粒尺寸越小、数目越多、分布在基体表面的比例越大,颗粒的增强效果越好;颗粒的大小和空间位置分布越均匀,复合材料抗循环变形的能力越强;球形颗粒和均匀分布的假设可以得到很好的模拟结果。

英文摘要：

Based on the mesoscopic finite element model of particle reinforced composites,the effects of stochastic properties of SiC particles on the ratcheting behavior of SiCP/6061Al composites were numerically analyzed by employing a 3D multi-particulate unit cell and using an advanced cyclic plastic constitutive model.In the simulation,a 3D multi-particle unit cell containing the stochastic particle properties was first generated by the random sequential adsorption（RSA） method,and then the effects of the number of particles,the particle arrangement,shape,size and their stochastic distributions on the ratcheting of the composites were discussed by the numerical simulations.The results show that the smaller the particulate size and the higher the proportion of the particles distributing near the surface of matrix as well as the more the number of particulates contained in the unit cell,the higher the resistance to the ratcheting deformation.Meanwhile,the modeled composite with uniform distribution of particle size and location presents higher resistance to the ratcheting deformation than that with random distribution.The assumptions of spherical particle and its uniform distributions in size and location in the 3D unit cell can provide a reasonable simulation to the ratcheting of the particle reinforced metal matrix composites.