特殊螺纹接头密封可靠性数值分析

Simulation Calculation Analysis of Seal Reliability of Premium Thread Connection

在实际加工中,金属对金属密封结构的特殊螺纹接头的参数是变化的,金属密封面上接触压力也是变化的。利用有限元概率分析功能建立了研究密封面上接触压力分布的方法,分析了特殊接头在锥度、密封直径、载荷等多个参数在随机变化条件下的密封面接触压力的分布规律,计算了密封可靠性。结果表明,不合适的螺纹参数匹配将导致密封面在拉伸载荷作用下失去密封能力。使用该特殊螺纹接头可靠性分析方法有助于优化螺纹密封结构与参数加工公差设计,进行管柱的可靠性设计与剩余寿命评估,提高接头的密封可靠性。

For premium thread connection with metal-metal seal, the reliability of seal is very important. In fact, the geometric parameters of connection vary in the determined scope which leads to the variation of contact pressure on the seal surface. The investigation method of contact pressure distribution with finite element analysis and calculation of the reliability of premium connection seal was established. The result showed that the improper combination of geometric parameters would bring the zero contact pressure to the premium connection seal surface under tension load,which means that the connection has lost the seal ability. The reliability analysis would help to optimize the designing of the machining tolerance of premium thread connection structure and to analyze the reliability and residual life of tubing and casing string and will help to improve the seal reliability of premium thread connection.