混合机织复合材料低速冲击损伤有限元分析

将二维机织碳布和单向碳布预浸料按照一定比例铺设成的混合机织复合材料兼具比刚度、比强度高、抗低速冲击损伤以及工艺性好等优点.采用基于三维非协调层合元的动力学有限元分析方法,对由二维机织缎纹碳布和单向碳布混合铺设而成的复合材料层合板进行了低速冲击有限元计算分析.针对二维机织碳布的特殊力学性质,提出了修正的分层扩展判据,建立了低速冲击损伤面积的分析方法.在不同冲击能量下,针对不同铺层结构和厚度的计算结果与试验结果皆吻合的很好.分析结果表明,由于分层破坏机理不同,加入机织铺层后能够有效降低低速冲击导致的分层损伤.

Finite Element Analysis of Low-velocity Impact Damage of Mixed Woven Composites

The mixed woven composites being laid up by 2D woven and unidirectional carbon prepreg alternately have the advantages of high specitic stiffness, specific strength and impact performance, and the processibility is good also. In this paper, using dynamic finite element method based on 3D nonconforming layered element, alow-velocity impact finite element analysis of 2D mixed woven composite laminates is performed. The laminates are laid up by 2D woven and unidirectional carbon prepreg alternately. In order to calculate the damage area, the modified delamination criteria are proposed to deal with the special mechanical prokertic of 2D woven carbon prepreg. The results of computer simulation are consistent well with these of experiment under different impact energies, different stacking structures and different thicknesses. It is found that the damage area is reduced effectively when there are woven plies in the laminates because of the different delamination mechanisms of the classical unidirectional plies.