弯管承受内部载荷压力和扭曲力矩时的蠕动变形计算

Calculation of Creep Distortion in Bend Subjected to Inside Pressure and Distortion Moment

提出特征应力法进行弯管使用寿命的估算,能够明显地计算出弯管蠕变的移动速度,大大地减少计算工作量。

The rupture in view of creep often occurs in the bends of piping used in industrial boilers. Apart from the causes in chemical and physical as pects, the methods usually used to assess and predict the piping life exist some disadvantages. These methods develop equations mainly depending on the geometry of bend, internal pressure and external moments, and the solutions are found by using variation method. The geometric parameters include the curve radii, the oval of the section and deviation of the round shape in section. This method needs to separate the section of the bend into infinite elements, which involves a large work. A method called feature stress method was presented in this paper to estimate the life of bends. Use of this method can obtain the creep rate occurred in bends, at the same time, the work of calcnlation can be decreased in a large amount.