热固性复合材料固化过程三维有限元模拟和变形预测

Three-dimensional finite element simulation and prediction for process-induced deformation of thermoset composites

分析了复合材料热固化过程中各种复杂的物理化学变化之间的相互影响,在此基础上建立了复合材料固化过程数值模拟和固化变形预测的三维有限元分析模型。采用整体-子模块方法将固化过程分为热-化学、流动-压实和应力-变形三个相对独立的子模块。热-化学模块的控制方程基于Fourier热传导方程和树脂固化动力学方程建立,解决了温度和固化度之间的强耦合问题。流动-压实模块的控制方程基于Darcy定律和有效应力原理建立,反映了树脂流动和纤维网络紧密压实之间的流固耦合关系。应力-变形模块建立了考虑热载荷和固化收缩载荷时复合材料层合板的有限元方程。各模块之间的相互作用通过它们之间的数据交换来实现,以树脂在固化过程中的凝胶点和玻璃化转化点为判断依据确定是否运行各模块及其子程序。典型结构的计算结果与实验对比验证了本文三维有限元模型的有效性。

On the basis of analyzing the interrelationship of the complex physical and chemical phenomena in the composite cure process, a three-dimensional （3D） finite element analysis （FEA） model was developed for simulating the process and predicting the process-induced deformation. By an integrated sub-model approach, the cure process was divided into three relatively independent modules： thermo-chemical, flow-compaction and stress-deformation. The thermo-chemical module was based on the Fourier＇s heat conduction and cure kinetics equation with the consideration of the coupling relation between temperature and cure degree. In the flow-compaction module, Darcy＇s law and effective stress principle were employed to describe the interaction between resin viscous flow and fiber bed consolidation. In the stress-deformation module, multi-layer complex composite laminates subjected to thermal load and resin cure shrinkage were analyzed by the 3D finite element method. Which module and its subroutines should be called was determined by resin gelation and vitrification. The interaction of these three modules is realized through exchanging the data between them. The representative structure simulation comparison with experiment verified the 3D FEA model in this paper.