薄壁金属内衬复合气瓶自紧压力的有限元分析及性能研究

PERFORMANCE STUDY AND FINITE ELEMENT ANALYSIS OF AUTOFRETTAGE PRESSURE OF THIN-WALLED METAL-LINED COMPOSITE GAS CYLINDERS

本文研究自紧压力对薄壁金属内衬复合材料气瓶性能的影响规律。采用有限元分析方法对气瓶的自紧过程进行数值模拟,缠绕成型复合材料气瓶,进行水压疲劳及爆破试验验证,并在试验过程中引入声发射监测。试验及分析结果表明,自紧压力对薄壁金属内衬复合材料气瓶的疲劳及爆破性能影响较大,自紧压力过大会使得气瓶复材层出现树脂开裂、纤维断裂等损伤,导致复合气瓶爆破强度值下降。疲劳试验结果表明,自紧压力过大容易导致薄壁内衬提前进入屈服状态,降低疲劳寿命。针对薄壁金属内衬复合材料气瓶,其自紧压力的选取必须充分考虑金属内衬在自紧及工作过程中的应力值,使其在合理区间。

The effect of autofrettage pressure on the performance of thin-walled metal lined composite cylinders was studied.The finite element method was used to simulate the autofrettage process of the cylinder,and the composite cylinders were wound to verify the hydraulic fatigue and blasting test.Besides,the acoustic emission monitoring was introduced into the test process.The experimental and analytical results show that the autofrettage pressure had great influence on the fatigue and blasting performance of thin-walled metal lined composite cylinders.The excessive autofrettage pressure would lead to resin cracking and fiber breakage in the composite layer of gas cylinder,which would reduce the burst pressure strength of composite gas cylinder.The fatigue test results show that excessive autofrettage pressure could easily lead to the lining to enter the yield state ahead of time and reduce the fatigue life.For thin-walled metal lined composite cylinders,the selection of autofrettage pressure should fully consider the stress of metal lined cylinders in autofrettage and working process,so as to make them in a reasonable range.