【摘要】 运用空间轴对称弹塑性有限元方法和混合律模型，推导出应力应变分配系数的解析表达式，并由此提出了一种新的定义复合材料比例极限和屈服强度的方法，进而研究了材料参数（纤维长径比、纤维体积分数、纤维根间距和基体应变硬化指数）对短纤维金属基复合材料拉伸变形行为的影响．研究表明，应力应变分配系数及其变化速率可以定量描述复合材料的屈服行为及应力分配作用；低应变阶段的应力应变分配系数与复合材料弹性模量之间存在确定的关系．该方法可以反映出材料参数对复合材料屈服行为的影响，预测的弹性模量和屈服强度与实验结果及Ｅｓｈｅｌｂｙ模型吻合很好。更多还原

【Abstract】 Based on the large strain axisymmetric elasto-plastic finite element and the law of mix- ture, a new method for defining the yielding behavior of metal matrix composite was proposed and an analytical expression for the coefficient of stress and strain distribution was derived. The effect of the material parameters (fiber volume fraction, fiber aspect ratio, fiber end distance and matrix strain hardening coefficient) on the deformation behavior of short fiber reinforced metal matrix composite was investigated. It was demonstrated that the stress strain partition parameter can be used to describe the stress transfer effect quantitatively and there is a determinate relation between the stress strain partition parameter and the elastic modulus of composite. The effect of material parameters on initial yielding behavior is shown more appropriately by this new method. The predicted elastic modulus and yielding stress are in good agreement with the experiment and also with the Eshelby model.更多还原