碳纤维缠绕复合气瓶自紧力和疲劳的数值模拟

Numerical Simulation of Autofrettage and Fatigue of Filament Wound Pressure Vessel

采用数值模拟方法研究了自紧工艺对碳纤维缠绕复合气瓶的应力分布和疲劳性能的影响。基于ANSYS商用有限元分析软件,考虑气瓶封头部分碳纤维缠绕层的角度和厚度沿封头子午线的连续变化,建立了有限元模型。分析验证了54 MPa自紧压力对复合气瓶零压和35 MPa工作压力下内衬和复合材料缠绕层应力的影响,并利用Coffin-Manson公式预测了复合气瓶的疲劳寿命。结果表明,自紧后复合气瓶内衬在工作压力下的最大应力减小了29.1%。有限元计算的疲劳寿命结果与实验测定结果之间的误差<8%,验证了有限元模型和计算方法的正确性。

The effect of autofrattage on stress distribution and fatigue life of composite overwrapped pressure vessels （COPV） was studied by using the numerical simulation. The finite element model of COPV was established based on the commercial software ANSYS. The variations of the thickness and winding angles of the composites along the meridian in the domes section are considered during the modeling. The influence of autofrettage pressure of 54 MPa on the stress of metallic liner and composite layers is analyzed. The fatigue life of the COPV is predicated by using Coffin- Manson formula. The results demonstrated that the diversity between the result of finite element analysis and the experiments is within 8% ,which indicated the finite element model and the analysis is reasonable.