气瓶内衬屈服强度对环缠绕复合气瓶疲劳性能影响的研究

为考察气瓶内衬材料的屈服强度对环缠绕复合材料气瓶(CNG-Ⅱ)性能影响,利用有限元数值模拟的方法,在气瓶的结构参数、纤维缠绕层参数、内衬材料的抗拉强度、自紧压力一定的情况下,研究内衬屈服强度变化对气瓶疲劳寿命的影响。有限元分析结果表明,随着内衬材料屈服强度的增加,CNG-Ⅱ复合气瓶的自紧效果变差,工作压力下所受环向平均应力增大,疲劳寿命降低。同时,对三种不同规格尺寸的环缠绕气瓶在不同屈服强度下的疲劳试验数据进行分析,进一步验证了复合气瓶的寿命随着内衬屈服强度的增加而减小。因此,在CNG-Ⅱ复合气瓶的生产过程中,有必要在一定程度上降低内衬的屈服强度,以改善复合气瓶的性能。

Research on Effect of Yield Strength of Liner Material on Fatigue Performance of Hoop-Wrapped Composite Cylinder

In order to investigate the effect of yield strength of the liner material of the cylinder on the performance of CNG-Ⅱ hoop-wrapped composite cylinder,the effect of yield strength variation of liner material on fatigue life of the cylinders was studied by finite element numerical simulation under the condition of constant structural parameters of the cylinder,parameters of fiber-wrapped layer,tensile strength of liner material as well as the self-tightening pressure of the cylinder.The results of finite element analysis show that with the increase of the yield strength of the liner material,the self-tightening effect of CNG-Ⅱ composite cylinder becomes poorer,average circumferential stress of the cylinder under working pressure decreases and the fatigue life decreases .Moreover,the fatigue test data of three sizes of hoop-wrapped composite cylinders with different yield strengths of liner material were analyzed,which further verified that the fatigue life of the cylinder decreases with the increase of the liner yield strength.Therefore,it is necessary to reduce the yield strength of the liner material to certain degree during the production of the CNG-Ⅱ composite cylinder in order to effectively improve the performance of the cylinder.