采用二元模型对短纤维增强复合泡沫(SFRSF)材料进行了简化模拟,考虑了纤维在空间中分布的随机性,并分别采用不同单元类型在不考虑网格匹配的情况下对纤维和基体单独进行网格划分。之后,采用改进的单元嵌入技术(EET)耦合纤维与基体的自由度,并引入杆单元模拟界面相,描述了材料内部纤维与基体的传载机制,从而建立了能反映材料细观结构的有限元数值模型。在此基础上,研究了碳纤维含量和长度以及空心微珠含量和壁厚对SFRSF杨氏模量的影响规律。结果表明,该数值模型对SFRSF杨氏模量的预测与实验值吻合较好。增加碳纤维的含量和纤维长度能够有效提高SFRSF材料的杨氏模量,适当增加空心微珠壁厚一定程度上可以增加其杨氏模量。
The binary model was used to simplify the simulation of short fiber reinforced syntactic foams(SFRSF).The randomness of fiber distribution in the space was considered,and the fiber and the matrix were separately divided by different element types without considering the mesh matching.Then the improved embedded element technique(EET)was used to couple the fiber and the matrix.A link element was introduced to simulate the interface and the force transfer mechanism between the fiber and the matrix.Then,a finite element numerical model was established to reflect the mesostructure of the material.Based on the numerical simulation,the influence of the length and content of fiber as well as the content and the wall thickness of hollow particle on the Young's modulus of the SFRSF was studied.The results show that agood agreement can be achieved between the numerical predictions and experimental observations.The increase of the content the length of carbon fibers and the wall thickness of syntactic foam can effectively improve Young's modulus of SFRSF.