多角度交替缠绕复合圆筒的剩余应力算法及水压试验

摘要

In order to calculate the residual stress of CFRP layers and metal liner for composite cylinders consisting of alternate multi-angle CFRP winding layers and thin-walled metal liner,a superposition algorithm layer by layer for CFRP layers and metal liner residual stress was proposed,reflecting on the thick walled cylinder theory and the elastic superposition theory of orthotropic material,and the effect of removing mandrel was under consideration as well.The influence of the spiral layers winding angle and the thickness of mandrel on the residual stress of CFRP layers and steel liner was analyzed with constant winding tension.The greater the thickness of mandrel,the lower the residual stress of CFRP layers is,but too thick mandrel weakens the enhancement effect of steel liner profiting from winding tension.When the spiral winding angle is in 65°,the residual stress of hoop layers is minimum,and the residual stress of spiral layers and steel liner is maximum.For the enhancement effect for steel liner,the yield loading pressure of steel liner was measured by the acoustic emission characteristics of the steel liner and the strain measurement of composite cylinder outer edge in the loading process based on water-pressure test.The test results were basically consistent with the theoretical prediction values and the validity of the algorithm proposed above was verified.A optimization design ideal of fibra intertwist tension system for composite cylinder with alternate multi-an-gle winding layers,which withstands an internal pressure load,was proposed to improve the winding quality,based on the hypothesis of equal residual stress in hoop and spiral layers,respectively.%针对含薄壁钢内衬碳纤维增强聚合物基复合材料(CFRP)多角度交替缠绕复合圆筒的剩余应力计算问题,基于正交各向异性材料的厚壁圆筒理论和弹性叠加理论,提出了考虑卸去芯模影响的多角度交替缠绕下CFRP各层和钢内衬剩余应力的逐层叠加算法,研究了恒缠绕张力下,芯模厚度和螺旋层缠绕角对 CFRP 各层和钢内衬剩余应力的影响.计算表明:芯模厚度越大则CFRP层剩余应力越低,但芯模厚度过大将减弱缠绕张力对钢内衬的强化效应;螺旋层缠绕角约 65°时,环向层剩余应力出现极小值,螺旋层剩余应力和内衬剩余应力均出现极大值.针对缠绕张力对钢内衬的强化效应,通过水压试验加载过程中钢内衬声发射特征与复合圆筒外壁应变测试,测得的钢内衬屈服载荷与理论预测值一致,基本证实了算法的有效性.为提高 CFRP 层缠绕质量,基于等剩余应力假设,提出了多角度交替缠绕张力制度优化设计思路,适用于内压管的张力制度优化.