复合材料压力容器的概率和非概率可靠性设计

Probabilistic and Non-probabilistic Reliability Design of Composite Pressure Vessels

考虑复合材料压力容器结构中各参数和载荷的随机性或区间性,利用基于概率的网格法得到其纤维强度发挥系数随机函数的计算表达式。建立了该类压力容器的可靠性分析模型,并分别应用随机因子法和区间因子法导出了纤维强度的均值、标准差和离差的计算表达式,利用概率的和非概率的可靠度计算方法,实现了该类压力容器的概率和非概率的可靠性设计,并考察了结构各不确定性参数的波动对容器厚度设计尺寸的影响。算例结果表明:概率和非概率的可靠性设计结果均可满足安全要求,且比传统的安全系数法结果更为精确与合理;概率方法相比非概率方法,其结果相对误差较小,但计算过程较为复杂。

Considering both randomness and range of physical parameters and applied loads of the composite pressure vessels(COPV),the netting theory based on probability was applied to obtain the random function’s computational expression of fiber strength exploitation coefficient,including establishing COPV reliability-analyzing model and making use of random factor method and interval factor method to deduce computational expressions of mean value,standard deviation and deviation of the fiber strength,and utilizing probabilistic and non-probabilistic reliability calculation method to implement COPV’s probabilistic and non-probabilistic reliability design and inspecting fluctuation influence of structure’s uncertain parameters on COPV design thickness.The numerical results show that both probabilistic and non-probabilistic reliability design results can meet safety requirements,it’s more accurate and reasonable than the traditional safety factor method.Compared with the non-probabilistic method,the probabilistic method has smaller relative error,but the calculation process is more complicated.