多尺度方法预测复合材料层板裂纹扩展

为了研究复合材料层板在细观和宏观尺度上的损伤分布，文中基于高精度通用单胞细观力学模型，发展了一种多尺度分析方法．该方法只需纤维和基体的材料属性、强度参数及纤维体积含量，而无需复合材料层合板的弹性参数和强度参数．文中使用该方法分析了复合材料结构的宏细观上的应力应变场;结合多尺度损伤模型，研究了复合材料的细观损伤以及宏观的裂纹扩展；通过二次开发ANSYS／LS-DYNA软件，文中将高精度通用单胞细观力学模型编译到用户自定义材料子程序中;使用这种方法分析了开孔层板轴向拉伸条件下的各个分层的应力分布、组分失效模式和裂纹扩展．并将计算结果与实验结果对比，结果表明: 数值模拟随时间变化的应力曲线与实验所得的曲线能较好的吻合; 预测的裂纹扩展与实验结果比较吻合．

Predicting the crack extension of composites based on the multi-scale method

In order to investigate the failure distribution of composites on micro and macro scales, this paper proposes a multi-scale method based on the High-Fidelity Generalized Method of Cells (HFGMC), which is applied to acquire strains and stresses on the macro scale, as well as on the micro scale. Combined with the multi-scale damage model, the component damages and crack extension are studied. The micro mechanics model requires fiber／matrix properties, strength parameters and the fiber volume rather than the properties and strengths of composites. The structural module requires further development for implementation of HFGMC into FE software ANSYS-LSDYNA via the user defined material subroutines (UMAT), which is used to analyze the stress distribution, components damage, and crack extension of laminates under the axial tensile condition. The calculated results are compared with the experimental results. The result indicates that the numerical load-stress curves agree with the experimental curves very well and that the predicted crack extension coincides with the experimental results.