蠕变-疲劳载荷下高温法兰连接系统的紧密性及评价方法研究

项目名称： 蠕变-疲劳载荷下高温法兰连接系统的紧密性及评价方法研究

项目编号： No.51305310

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 郑小涛

作者单位： 武汉工程大学

项目金额： 25万元

中文摘要： 针对石化行业高温法兰连接系统在蠕变-疲劳载荷下长周期安全运行的难题，以柔性石墨金属波齿复合垫片连接为研究对象，以建立极端条件下法兰连接系统的紧密性理论及基于完整性的安全评价方法为目标，主要从两个方面取得突破：其一，开展法兰连接系统及各连接部件的蠕变-疲劳实验，重点探索变形协调下法兰连接系统泄漏率的时间-频率相关性、自松弛和应力松弛耦合作用下螺栓松动机制和柔性石墨金属波齿复合垫片的复杂泄漏模型，揭示其在蠕变-疲劳载荷下的密封机理和失效模式；其二，研究高温法兰连接系统完整性的关键控制参数，建立以安定性准则、蠕变-疲劳损伤及时间-频率相关的紧密度理论为基础的安全评价方法。本项目内容涉及固体力学、渗流力学、传热学和材料学等多学科领域，可望在蠕变-疲劳载荷下高温法兰连接系统的失效机理及完整性评估等方面取得突破，为极端条件下高参数法兰连接系统的可靠性和安全运行提供技术支持。

中文关键词： 蠕变；疲劳；棘轮；泄漏率；紧密性

英文摘要： Considering the problems of the long-term security operation of high-temperature flanged connections under creep-fatigue loadings in petrochemical industry, with the goal of establishing the tightness theory of high-temperature flanged connections with flexible graphite corrgated metal gasket(FGCMG) and its safety assessment methods based on integrity theory under extreme conditions. Two main questions will be investigated intensively. Firstly, to reveal the sealing mechanism and failure mode of high-temperature flanged connections under creep-fatigue loadings, material characteristic of connecting parts and sealing performance of real systems under creep-fatigue conditions are studied by experimental tests. The time-frequency dependent leakage rate, bolting loosening mechanism produced by self-loosening and stress relaxation interaction under the compatibility condition of connection systems and the complex leakage model for FGCMG will be stressed. Secondly, to ensure the integrity of high-temperature bolted-flange connections, the key control parameters affecting safety operation are deeply investigated. The safety assessment methods based on the shakedown theory, creep-fatigue damage as well as time-frequency dependent tightness theory are established. This project involves in the realms of Solid Mechanics,P

英文关键词： creep；fatigue；ratchet；leakage rate；tightness