复合材料压力容器金属内胆自紧后的屈曲可靠性分析

Buckling reliability analysis of the metal liner of composite pressure vessel after autofrettage

建立了一种针对复合材料压力容器金属内胆自紧后的局部屈曲可靠性分析方法。基于凹陷对内胆界面压力和残余弯矩影响的解析模型,结合有限元数值仿真分析方法,进行了金属内胆局部屈曲分析;基于蒙特卡洛算法,建立了分别针对复合材料压力容器内胆和缠绕层设计变量的抽样方法;采用径向基函数(Radial basic function,RBF)代理模型替代了内胆屈曲计算的有限元分析模型,建立了自紧后压力容器金属内胆局部屈曲可靠性问题的快速分析方法。以30 L柱形纤维缠绕复合材料铝合金内胆压力容器为例,分析了内胆设计参数与缠绕层设计参数不确定性对内胆屈曲可靠性的影响。结果表明:在计算范围内内胆屈曲概率与自紧压力正相关;内胆厚度的随机性对压力容器内胆屈曲概率的影响随自紧压力增加呈近似直线增加;单独考虑内胆半径、缠绕层厚度及缠绕层模量,屈曲概率随自紧压力变化趋势为一条增速先缓再快再变为平缓的递增曲线。

A buckling reliability analysis method for the metal liner of composite pressure vessel was established.Based on the analytical model of influence of the depression on the pressure and residual moment of the liner interface, the local buckling analysis of the metal liner was carried out by combining the finite element numerical simulation analysis method. Based on Monte Carlo algorithm, sampling methods for design variables of composite pressure vessel liner and winding layer were established, respectively. The radial basic function(RBF) surrogate model was used to replace the finite element analysis model for the buckling calculation of the inner liner, and a fast analysis method for the reliability of the local buckling of the pressure vessel with metal liner after autofrettage was established. Taking a 30 L cylindrical fiber wound composite pressure vessel with metal liner as an example, the influence of the uncertainties of the design parameters of the inner liner and the winding layer on the buckling reliability of the inner liner was analyzed. The results show that the buckling probability of the liner is positively correlated with the autofrettage pressure within the calculated range. The influence of the liner thickness on the buckling probability of the liner increases approximately linearly with the increase of the autofrettage pressure.Considering the liner radius, the thickness of the winding layer and the modulus of the winding layer separately, the variation trend of the buckling probability with the autofrettage pressure is an increasing curve from slow to fast and then to gentle.