基于三维Puck失效准则及唯象模量退化的复合材料臂杆屈曲分析

摘要

针对碳纤维增强树脂基复合材料(CFRP)臂杆结构在压缩和扭转载荷条件下屈曲与后屈曲问题,采用三维Puck失效准则和基于唯象分析的模量退化方法,同时考虑层合结构就位效应及沿纤维方向应力对横向强度的影响,建立了一种适用于考虑渐进失效CFRP结构的屈曲分析方法,并通过编写有限元软件ANSYS的USERMAT子程序进行了数值实现.与文献中实验结果的对比表明,上述方法能够分析复合材料结构的渐进失效过程和后屈曲承载特性,预测精度高.进而采用此方法,详细分析了某航天器臂杆结构在承受压缩与扭转载荷条件下的屈曲载荷及后屈曲特性.%The buckling and post-buckling analyses of carbon fiber reinforced epoxy-matrix composite (CFRP) arm under compressive and torsional loading conditions were addressed based on three-dimensional Puck failure criterion and phenomenological modulus degradation method.Taking into account the in-situ effect of the laminated structure and the effect of stress along the fiber direction on the transverse strength, a buckling analysis method considering progressive failure process of CFRP structures was established.The numerical implementation was realized by ANSYS material subroutine USERMAT.It is verified by comparing with the experimental results in the literature that, the new method can analyze the progressive failure process and post-buckling behavior of the composite structures with high accuracy.Furthermore, this method was used to analyze the buckling load and post-buckling behavior of a spacecraft composite arm under compressive and torsional loads.