内压下管道三通的极限载荷解

Limit load solution for the piping branch junction under mternal pressure

介绍了通过相贯线支管侧和主管侧内力之间的关系求取焊制三通塑性极限载荷 的工程方法。即首先由简单的力平衡方程获得支管在相贯线处的内力与极限载荷的关系,将此 内力作为主管相贯线处的外力,继而求解极限载荷状态下主管近相贯线处内力的近似解,结合 Von—Mises屈服条件(即三通由于相贯线主管侧形成塑性铰而失效时内力需满足的条件), 便可获得三通的塑性极限载荷,并据此建立了管道三通塑性极限压力的估算式。

An engineering analysis approach for plastic limit load of weld piping tees, by the relationship of internal force between run and branch pipe around the intersection, is presented in this work. The approach is built on the following process： First of all, an equation between the limit load and internal force of branch pipe surrounding the intersection should be founded based on the force equilibrium condition. Secondly, regarding this internal force as external force acting on the intersection of run pipe, the approximate solutions of internal force around the intersection on run pipe, under the plastic limit load, can be given. Finally, recurring to the Von-mises yield criterion, the plastic limit load of two intersecting cylindrical shells can be obtained. By using this approach, an approximate plastic limit load solution of weld piping branch junction under internal pressure is obtained.