输油管道螺纹联接处接触应力分析

Analysis on Contact Stress in the Thread Connection of Oil Pipe

1 前言 在高温、高压输油管道中,管道和法兰一般采用螺纹联接方式,并在管道端部加上密封垫,然后用螺栓给两个法兰施加预紧力,以实现管道接头处的联接和密封,见图1。正常工作时,管道在内压力、输送油品的温度变化和螺栓预紧力的共同作用下,管道和法兰的螺牙表面将产生很大的接触压力,螺牙根部将出现很大的局部应力,这种接触应力的分布规律很难用解析法求得。为此。

According to the theory of elastic contact, the artical, using finite element mixing method, analyses contact stress in the thread pipe connection. Examples are given and contact stresses calculated. Calculations show that the greatest stress of flange concentrates on the first thread root of the upper end, and that of pipe falls on the third root beyond where pipe contacts flange, and a minimum zone comes into yield condition. The article provides theoretical basis for stress checking of pipe flange thread, design of structures and analysis on seals properties.