Study on the Sealing Performance of Pipe Flange Connections at Elevated Temperature by Computational Mechanics

1.考虑接触热阻的温度分析程序将接触热阻的经验公式引入商业程序中，建立了高精度的三维温度分析数值程序，该程序可以处理热行为和结构分析。螺栓联接周围热流模式及螺栓预紧力变化机理的研究利用上述方法，较全面地阐明了所提供的热量在螺栓联接周围的流动情况以及轴向螺栓受力的变化幅度。热载荷作用下管法兰连接的温度和应力分析采用精确几何的管法兰模型，分析了管法兰的温度和应力场，并评估了管法兰热变形引起的轴向螺栓力的变化。片状垫片高温压缩试验装置的研制一种压缩试验装置，可产生高达30 MPa的压缩压力，并可将垫片温度提高高达300℃。已经被开发出来。获得了从室温到150℃不同温度下片状垫片的压缩曲线。高温下垫片材料性能对密封性能的影响利用得到的压缩曲线，研究了高温下垫片刚度的变化对密封性能的影响。高温下管法兰连接的紧固操作导则为了建立高温下管法兰连接的紧固操作指南，建立了一套数值计算程序，为分析管法兰连接的热性能和力学性能提供了坚实的基础

1. Numerical Procedure for Temperature Analysis by Taking Account of Thermal Contact resistance A three-dimensional numerical procedure with high accuracy for temperature analysis has been established by incorporating the empirical equation for thermal contact resistance into a commercial program which can deal with thermal behavior and structural analysis.2. Elucidations of the Heat Flow Pattern around Bolted Joint and the Mechanism of Bolt Preload Variation It has been comprehensively elucidated using the above method how the supplied heal flows around the bolted joint and the magnitude of axial bolt force varies.3. Temperature and Stress Analysis of Pipe Flange Connections subjected to Thermal Load Using pipe flange models with accurate geometry, its temperature and stress fields were analyzed, and the variations of axial bolt force due to the thermal deformation of pipe flange have been evaluated.4. Development of Compression Test Equipment for Sheet Gaskets at Elevated Temperature A compression test equipment which can generate the compressive pressure up to30MPa and increase the gasket temperature as high as 300 deg. has been developed. Compression curves of sheet gaskets were obtained at various temperatures from room temperature to 150 deg.5. Effects of Material Properties of Gaskets at Elevated Temperature on the Sealing Performance Using the compression curves so obtained, it has been investigated how the stiffness variation of gaskets at elevated temperature affects the tightening characteristics.6. Guideline for the Tightening Operation of Pipe Flange Connections at Elevated Temperature In order to establish a guideline for the tightening operation of pipe flange connections at elevated temperature, a numerical procedure, which provides a rigid foundation to analyze thermal and mechanical behaviors of pipe flange connections, has been established