薄壁内胆碳纤维全缠绕复合材料气瓶轴向残余变形及屈曲分析

Residual Axial Deformation and Buckling Analysisof Thin-Walled Carbon Fiber Fully WoundComposite Gas Cylinders

针对钛合金薄壁内胆碳纤维全缠绕复合材料气瓶水压试验后轴向缩短及内胆局部发生屈曲失稳现象,开展了试验研究及有限元分析.结果表明:自紧加卸载后,封头靠近极孔区域沿轴向向内凹陷,封头靠近赤道区域沿径向向外扩张,封头整体沿轴向变短,试验和有限元计算的轴向缩短量为6.15 mm和6.363 mm,误差为3.46%,有限元计算结果与试验结果具有很好的一致性.最后,采用多极孔法优化封头纤维层厚度分布,封头厚度极值降低32.6%,过渡更加均匀,优化后的气瓶沿轴向略有伸长,平均伸长为0.6 mm,采用CT和内窥镜检测,内胆均未出现屈曲失稳,有效地解决了水压试验后轴向缩短及内胆屈曲问题.

Experimental research and finite element analysis were carried out to study the phenomenon of axial shortening and buckling instability of carbon fiber fully wound composite gas cylinders with titanium alloy thin-wall liners after hydraulic test.The results show that,after self-tightening and unloading,the area near the po-lar hole of the head will be concave axially,the area near the equator of the head will expand radially,and the whole head will become shorter axially.The axial shortening of the head will be 6.15 mm and 6.363 mm,re-spectively,and the error of the finite element calculation will be 3.46%.The finite element simulation results are in good agreement with the experimental results.Finally,the multi-pole hole method was used to optimize the thickness distribution of the fiber layer of the head,and the extreme thickness of the head was reduced by 32.6%,and the transition was made smoother.After the optimization,the gas cylinder will be slightly extended along the axis,with an average elongation of 0.6 mm.By CT and endoscope detections,no buckling instability would appear in the liner,which means an effective solution of the problems of axial shortening and liner buckling af-ter hydraulic tests.