基于二阶矩法的内压圆柱壳可靠性设计

Reliability Design of Cylinder Vessels with Internal Pressure Based on the Second Moment Method

利用二阶矩法推导出内压圆柱壳基于弹性失效设计准则的中径公式、Mises公式和全塑性失效设计准则的Mises公式的可靠性系数的表达式,然后将其应用于一算例当中,比较内压圆柱壳的常规设计与可靠性设计.结果表明:利用同一失效准则的同一强度理论,内压圆柱壳的可靠性设计要比常规设计经济,且厚壁柱壳的经济性越发明显.基于二阶矩法的内压柱壳的可靠性设计准则的选择为:当计算压力较低时,选择基于中径公式推导出的可靠性系数表达式;当计算压力较高时,选择基于全塑性失效设计准则的Mises公式推导出的可靠性系数表达式.

The Intermediate Diameter formula and the Mises formula based on the elastic failure norm, and the Mises formula based on the whole plastic failure norm about the reliability of cylinder vessels with internal pressure were conducted with the second moment method. Then they were applied to an engineering case. The reliability design of cylinder vessels with internal pressure was compared with the rule design. The result has shown that the reliability design of cylinder vessels with internal pressure is more economical than the rule design under the same strength theory of the same failure norm. And when the thickness of cylinder vessel wall is thicker, the reliability design is more economical. The norm for selecting the reliability design based on the second moment is： when the pressure is lower, it is simple to select the Intermediate Diameter formula, and when the pressure is higher, it is reasonable to select the Mises formula based on the whole plastic failure norm.