拉挤型CFRP管轴压性能

Buckling behavior of pultruded carbon fiber reinforced polymer pipes under axially compressive load

航天器骨架结构通常由轻质高强CFRP(carbon fiber reinforced polymer)复合材料管制成,其稳定承载力成为结构安全性能的一项重要指标。对CFRP短管进行轴压试验,重点研究碳纤维增强复合材料的刚度、极限强度以及细观破坏模式。基于Hashin破坏准则进行二次开发,采用ANSYS有限元软件对试验过程进行了数值模拟,数值结果表明,Hashin破坏准则可以较好地预测CFRP复合材料破坏时的极限承载力。基于Hashin破坏准则,采用弧长法对试验工况中的5组长细比的CFRP细长管进行数值模拟,绘制荷载-跨中挠度曲线,总结其破坏特点、变形特征,与试验对比吻合较好。通过参数分析,并根据试验结果与数值分析结果,拟合得到了拉挤型CFRP细长管稳定系数Φ与长细比λ之间的关系曲线,方便工程使用。

The spacecraft skeletal structure is usually made of lightweight,high strength composite CFRP material,whose stability capacity is an important indicator of the structural safety performance. Firstly,pultruded CFRP short pipe compression test was done in this paper,focusing on the stiffness,ultimate strength and microscopic failure mode of carbon fiber reinforced resin matrix. Secondly,based on the Hashin failure criteria and using ANSYS finite element software to do numerical simulation showed that the numerical results from Hashin failure criterion can better predict the ultimate bearing capacity in the failure mode of CFRP composites. Next,the Hashin failure criteria are further compared with experiment by using the arc-length method to do numerical simulation for five types of CFRP slender pipes,rendering the load mid-span deflection curve of the whole process,summarizing the characteristics of its destruction,and deformation characteristics. The simulation results are in good agreement with experiment. Based on this,a large number of parameter analyses are evaluated and the experimental results are compared with the numerical analysis result. The relationship curve between stability factor Φ and slenderness ratio λ of the pultruded slender CFRP pipe was derived by the least squares fitting calculation. This research is convenient for the application in engineering practice.