基于有限单元法的平纹织物复合材料强度预测:2.复合材料层合板拉伸过程的有限元分析

针对实际使用中平纹织物复合材料铺层角度问题,将0°/45°/90°/-45°铺层的层合板作为有限元分析对象,研究其犬骨试验件在单向拉伸作用下的响应。分析过程中,将试样视作宏观均匀的弹性材料,利用已得出的平纹织物复合材料的物性值,以8节点块单元对模型进行离散,通过分步施加载荷,得到复合材料的应力与应变曲线。与实测值作对比发现,仿真结果同实测结果相吻合。将节点反力作为复合材料单胞模型的边界条件,对复合材料进行失效预测。结果表明:角度铺层设计可以减弱细观结构的开裂和分层;且在承受相同的拉伸应力下,铺层复合材料单胞内树脂单元失效的数量少,因此具有更高的强度。

Mechanical strength prediction of plain woven fabric composite: 2. finite element analysis of composite laminates under tensile stress

For the actual use of layer angle problems of the plain woven fabric laminated composite, a plain woven composite with 0°/45°/90°/ - 45° 4-layered laminates was prepared, and the dog-bone shaped specimen's stretch under unidirectional tensile stress was investigated. During analysis, the specimen was perceived to be a macro-uniformed elastic material. Finite element model was established. The laminates were meshed by 8-node-solid elements. By step loading, the stress - strain relationship was obtained by numerical simulation, which is in good accordance with the test result. To predict the strength failure, the node reactions were selected as the boundary conditions of the cell sub-model. The results showed that the angle-layered laminates have less cracks and delimitations than the one-way layered. Moreover, under the same stress, the damaged resin elements are less, too. This will bring the angle-layered laminates with a higher strength.