含缠绕层缺陷大容积钢内胆复合材料气瓶爆破压力分析

ANALYSIS OF BURST PRESSURE FOR LARGE VOLUME STEEL LINER COMPOSITE CYLINDERS WITH WINDING LAYER DEFECTS

采用有限元软件构建大容积钢内胆复合材料气瓶模型,并在缠绕层表面建立三个体积型缺陷。详细阐述了数值模型的构建过程,重点分析了在设计爆破压力(50 MPa)下含不同缠绕层表面缺陷的气瓶内胆和缠绕层应力分布及大小,通过最大应力准则预测了各自情况下的爆破压力,与气瓶水压爆破试验数据进行了对比,并在此基础上研究了不影响爆破压力的缠绕层表面临界缺陷尺寸。模拟结果表明:缺陷对内胆应力影响较小,但缠绕层应力会因此急剧增大;爆破压力则是明显减小,且深度对其影响更大;针对本文讨论的气瓶,给出了临界面积为200 mm×200 mm,临界深度为1 mm这一结论。

In the process of production and manufacturing,collision and friction would inevitably occur in the large-volume steel liner composite cylinder,which would cause damage on surface of the winding layer and reduce safety of cylinder.Because of the high cost of cylinder,it would cause great economic loss if cylinder with surface defect of winding layer was scrapped.Therefore,it was necessary to conduct finite element analysis on cylinders with winding layer defects.The finite element software was used to construct a large volume hoop-wrapped composite cylinder model,and three volume defects were established on surface of the winding layer.The process of numerical model and defect establishment were described in detail.Stress distribution and size of cylinder liner and winding layer with different winding layer surface defects were analyzed under the design burst pressure(50 MPa),and cylinder burst pressure in each case was predicted by maximum stress criterion.Then,the simulation results were compared with data of cylinder hydraulic burst testing.Critical size of winding layer that has no effect on burst pressure was studied base on the above discussion.Simulation results show that defects of winding layer had little effect on liner stress,but stress of winding layer would increase sharply,and burst pressure would obviously decrease and depth had a greater influence on it.For cylinder discussed in this paper,the critical size was that the area was 200 mm×200 mm and depth was 1 mm.