短纤维增强金属基复合材料拉伸变形的屈服行为的理论研究

运用空间轴对称弹塑性有限元方法的混合律模型，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。

THE THEORITICAL RESEARCH IN THE YIELDING BEHAVIOUR OF TENSILE DEFORMATION IN SHORT FIBER REINFORCED METAL MATRIX COMPOSITE

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.