复合材料板件热分层分析及试验验证

针对飞行器用复合材料层合板件的热应力分层问题，进行了试验与数值模拟方面的研究.采用双线性内聚力单元用于模拟层合复合材料的分层现象；通过二次交互应力准则判断复合材料刚度降阶的起始点；并同时使用幂指数准则作为材料在混合破坏模式下的失效准则.数值模型中单层复合材料的力学性能和热膨胀性能分别由在高温（70℃）、室温（23℃）、低温（-50℃）环境下的相应测试进行确定.各复合材料层合试验件在仪器DIL-402C中经历了相同的温度变化过程，最大温差相差120℃.试验后发现，对于给定铺层的试验件，其两端中间层发生了层间分层.将数值模拟的结果与试验结果进行对比，对比结果表明数值分析与试验结果吻合良好，由此也可证明此分析方法的可行性与正确性.

Thermal stress induced composite laminate delamination analysis and experiment verification

To solve thermal stress induced delamination in composite laminates that used in flying vehicles, experimental tests and numerical analysis were carried out. Bilinear controlled cohesive elements were adopted to simulate the delamination in laminates, quadratic failure criterion was used to predict the initiation of stiffness softening process, and power law criterion was applied to determine the delamination propagation under mix-mode fractures. The mechanical and thermal expansion properties of lamina applied in those numerical models were tested at high temperature (70℃), room temperature (23℃) and low temperature (-50℃) respectively. The delamination experiments were carried out by use of apparatus DIL-402C. Each composite laminate experienced a same temperature changes, and the maximum temperature difference was 120℃. After experiments, the laminates in given plies were found that delamination appeared in their mid-ply in both ends. Comparisons were made between experimental results and numerical analysis. Compared results show that the predicted delamination zone was well according with the experimental results, which would certify the rightness and reliability of this analysis method.