复合材料层合板固化压实过程有限元数值模拟及影响因素分析

根据有效应力准则和达西定律建立了描述复合材料固化压实过程层合板压缩和树脂流动的二维有限元方程, 节点自由度为位移和树脂压力, 采用向后差分方法直接耦合积分求解以提高收敛速度。数值计算结果表明: 随着层合板厚度的增加, 厚度压缩率减小, 固化压实所需时间增加, 树脂在厚度方向的不均匀性逐渐增加。对于厚度较大的层合板, 采用提高固化压力和双面吸胶两种工艺对比情况说明, 后者可以显著提高压实程度并得到相对均匀的树脂含量分布。 

Compaction of laminated composites: numerical simulation and analysis on influencing factors

A two dimensional finite elemental model is developed to simulate and analyze the compaction of the composite laminates during the autoclave processing.The model is based on the effective stress principle and Darcy's law.The resin pressure is chosen as the additional degree of freedom of the nodes.The coupled equations are solved by the backward difference and direct approach because of its rapid convergence.The results of the numerical simulation show that,with the laminated thickness increasing,the thickness reduction ratio decreases,and the compaction implementing time and the resin distribution unsymmetry in the thickness direction increase.For the thicker laminate,compared with enhancing cure pressure,placing bleeder at both sides of the laminates improves the thickness reduction ratio significantly and gains a more uniform resin distribution.