论文部分内容阅读
提出了一种改进的实验与数值混合法。该方法采用随机短纤维增强复合材料的紧凑拉伸实验,首先得到材料的宏观内聚力模型,进而确定该材料纤维基体界面微观内聚力模型参数。通过有限元法和基于场投影的反解法得到了宏观内聚力模型结果,对比分析这两个方法的结果,得出该反解法对误差的容忍度较低。随后采用改进的反解法,用数字图像相关法(DIC)直接获取宏观内聚力模型分离量,减少了该反解法未知数的数量,提高了容错率。再将DIC和改进的反解法结合,对该材料裂纹尖端宏观内聚力区的牵引力进行了反解。采用双线性内聚力模型,根据Mori-Tanaka方法,将求得的宏观内聚力定律与纤维基体界面微观内聚力定律关联起来,从而求得了纤维基体界面微观内聚力模型参数。该方法和结果可为短纤维增强复合材料纤维基体界面的微观力学分析提供实验基础。
An improved experimental and numerical hybrid method is proposed. In this method, a compact tensile test of random short fiber reinforced composites was carried out. The macroscopical cohesion model of the material was obtained first, and then the microscopic cohesion model parameters of the fiber matrix interface were determined. The results of macro cohesion model are obtained by finite element method and field projection based anti-solution. The results of these two methods are contrastively analyzed, and the results show that the anti-solution has a low tolerance to error. Then using the improved inverse method, the digital coherent correlation (DIC) is used to directly obtain the macrocosmic cohesion model separation, which reduces the number of unknowns and improves the fault tolerance. Then the combination of DIC and the improved anti-solution method is used to reverse the traction of the macro-cohesion zone at the crack tip of the material. The bilinear cohesion model was used to correlate the obtained macroscopic cohesion law with the microscopic cohesion law of the fiber matrix interface according to the Mori-Tanaka method. The microscopic cohesion model parameters of the fiber matrix interface were obtained. The method and result can provide the experimental basis for the micro-mechanical analysis of the fiber matrix interface of short fiber reinforced composites.