复合材料导管导流罩渐进失效分析

Progressive Failure Analysis of Composite Material Duct Dome

基于连续损伤力学(Continuum Damage Mechanics,CDM)理论对复合材料导管导流罩进行渐进失效分析,结合刚度降级方法从材料失效角度对导流罩结构极限承载能力和失效演变情况进行研究。利用APDL参数化语言编写程序建立复合材料导管导流罩有限元模型,应用多帧重启动及弧长法实现分析过程。根据Tsai-Wu失效准则判断复合材料损伤及损伤原因,并对失效单元进行连续记录。结果表明:复合材料导流罩结构最先出现基体开裂失效模式,此时少量破坏对导流罩整体结构性能影响较小;随着载荷继续增加出现纤维断裂失效模式;在纤维断裂大规模出现时,载荷位移非线性关系逐渐明显,结构性能急剧下降;整个过程几乎没有出现界面剪切失效情况。根据结构载荷位移曲线和失效单元数目变化情况,导流罩承载时的Tsai-Wu失效因子作为复合材料导管导流罩的强度校核指标具有理论和实际意义。

Based on the Continuum Damage Mechanics(CDM) theory,the progressive failure analysis of composite material duct dome is made.Combined with the stiffness degradation method,the ultimate bearing capacity and failure evolution of dome structure are studied from the perspective of material failure.The finite element model of composite material duct dome is established with APDL parametric language programming,and the analysis process is realized by multi-frame restart and arc-length method.According to Tsai-Wu failure criterion,the composite material damage and damage causes are judged,and the failure units are recorded continuously.The results show that:the matrix cracking failure mode appears first in the composite material dome structure,and at the moment a small amount of failure is of little effect on the overall dome structure performance;as the load continues to increase,the fiber fracture failure mode appears;when the fiber fracture occurs on a large scale,the nonlinear relationship of load-displacement becomes obvious gradually,and the structure performance declines sharply;there is almost no interface shear failure in the whole process.According to the structure load-displacement curve and failure unit number change,the Tsai-Wu failure factor when the dome is loaded is of theoretical and practical significance as the strength checking index of composite material duct dome.