Abstract:

In order to study the sealing performance of bolted flange connection system under high temperature condition, the thermal?structural coupling analysis of bolted flange connection system under 400.00 ℃ was carried out by Ansys?Workbench. The results show that the temperature decreases gradually from the inside of the flange wall to the outside, the maximum stress appears on the contact surface between the nut and flange, and the maximum strain appears on the gasket. Evaluated the sealing performance of gaskets at room temperature and 400.00 ℃; at the same time, aiming at the easy sealing failure of gaskets in the connection system under high temperature, established gasket strength failure of bayesian networks, based on a series of methods such as expert evaluation to calculate the prior probability, used Bayesian network reverse reasoning to calculate the posterior probability of the root node and sort them to find out the main factors leading to the invalid gasket, so as to enhance the reliability in the process of using gasket.

Key words: Ansys?Workbench, Thermal?structural coupling, Bayesian network, Bolted flange connection

摘要：

利用Ansys?Workbench，对400.00 ℃下的螺栓法兰连接系统进行热?结构耦合分析，研究了高温条件下螺栓法兰连接系统的密封性能。结果表明，温度从法兰内壁由内至外逐渐降低，最大应力出现在螺母与法兰盘的接触面上，最大应变出现在垫片上。对常温及400.00 ℃的垫片进行了密封评定，同时针对高温下连接系统中垫片易密封失效的问题，通过建立垫片强度失效的贝叶斯网络，基于专家评估等一系列方法计算得到先验概率，再利用贝叶斯网络反向推理计算根节点的后验概率并排序，找出导致垫片失效的主要因素，从而提高了垫片在使用过程中的可靠性。

关键词: Ansys?Workbench, 热?结构耦合, 贝叶斯网络, 螺栓法兰连接