纤维缠绕聚合物基复合材料压力容器的可靠性设计

为对纤维缠绕聚合物基复合材料( FWRP) 压力容器进行可靠性设计和安全测评, 引入可靠性理论; 应用统计学原理, 以同一失效概率为标准进行FWRP 压力容器结构设计, 以取代目前应用的传统安全系数法设计。根据国家标准制备8 个玻璃纤维缠绕复合材料( GFWRP) 压力容器, 通过实验获得纤维强度、缠绕角、几何尺寸、爆破压力等随机变量特征值。GFWRP 压力容器结构可靠性设计值(纤维缠绕壁厚) 与实验结果基本吻合, 并明显小于传统安全系数法设计值。通过对不同纤维强度随机分布可靠性设计理论计算结果的比较, 确知纤维强度的离散程度是FWRP 压力容器可靠性设计的重要影响因素。传统安全系数设计法只考虑纤维强度(均值) 大小, 而无视纤维强度随机分布特征值对FWRP 压力容器结构抗力的影响, 显然是不合理的。可靠性设计实现了安全性与经济性的有效统一。 

Reliability design of f iber wound reinforced plastics pressure vessel

For reliability design and safety evaluation on fiber wound reinforced plastics (FWRP) pressure vessels,the traditional safety factor design was substituted by a reliability structure design based on the reliability theory and the statistical principle.Eight glass fiber wound reinforced plastics(GFWRP) pressure vessels were manufactured and the experiments were conducted to obtain the probabilistic distribution of design variables,such as the fiber strength,winding angle,geometric size,burst strength and so on.The results(thickness of the winding fiber) derived from the reliability design agree well with the experimental results and much lower than that from the traditional safety factor design.Through comparison between the reliability design results with different statistics of fiber strength,the significant influence of the variance level of fiber strength on reliability design of FWRP pressure vessel was demonstrated.The traditional safety factor design was verified to be not reasonable since it considers only the mean value of fiber strength without the effect of fiber strength statistics on the structural resistance of the vessel.The reliability design of FWRP pressure vessel in this study presents the effective unity of safety and economy.