复合材料压力容器自紧后残余变形研究及有限元分析

研究复合材料压力容器自紧加卸载过程中的轴向残余变形趋势,揭示复合材料压力容器轴向残余变形机理与成因,对合理控制复合材料压力容器自紧过程中的尺寸稳定性具有重要研究和应用意义。主要针对碳纤维缠绕钛内衬压力容器自紧后出现的残余变形现象展开实验研究和有限元分析。结果表明,自紧加卸载后,钛内衬发生了塑性残余变形,为保证封头曲线的连续协调性,封头内衬向内凹陷,容器在轴向产生缩短变形趋势。此外,钛内衬材料屈服强度变化是容器轴向残余变形的显著影响因素,随着钛内衬材料屈服强度的增加,复合材料压力容器轴向残余变形量(缩短)减小,有限元分析结果和实验预测具有很好的一致性。

RESIDUAL DEFORMATION OF COMPOSITE PRESSURE VESSELS AFTER AUTOFRETTAGE AND ITS FINITE ELEMENT ANALYSIS

It is of great significance to carry out research on the trend of axial residual deformation of composite material pressure vessels as well as revealing the influence mechanism and the reasonable on axial residual deformation of pressure vessels,which is helpful to control dimensional stability of composite pressure vessel in service.In this paper,the important part is to have finite element analysis and experimental research on the axial residual deformation of composite material pressure vessels since the process of autofrettage.The results show that the plastic deformation occurrs in the titanium liner under work pressure.In order to ensure the head curve of continuous coordination in the progress of autofrettage,the head liner inward concave and pressure vessels have the trend of axial shortening deformation.In addition,the change of yield strength of titanium liner has obvious effects on the trend of the axial residual deformation of pressure vessel.With the increase of titanium liner material yield strength,axial residual deformation of composite pressure vessel (shorten) decreases,and the better consistency between finite element analysis with experimental prediction results has been proven.