第1部分:螺栓法兰接头的三维有限元建模和用于测量垫片接触应力的传感器的开发:承受外部弯曲载荷的螺栓法兰接头的三维有限元建模在现实生活中，螺栓法兰接头可能承受来自许多不同来源的外部载荷，包括管道和管道组件的热膨胀、管道支架的错位，以及接头部件的非对称热膨胀。在大多数情况下，弯矩会在管道中产生，并传递到法兰上。对于螺栓法兰接头的设计，必须考虑这些力矩的影响，因为它会影响其机械和密封性能。 使用有限元技术分析承受非对称载荷的螺栓法兰是强大且经济的。对于大尺寸法兰尤其如此，因为其实验测试非常昂贵且难以实现。1996年，TTRL[1]曾尝试利用傅里叶展开法将三维载荷转换为二维载荷，建立具有非轴对称载荷的有限元模型。使用该模型获得的结果并不令人满意，因为未考虑螺栓接头行为的非线性。对于非对称载荷，使用关节组件的三维建模当然更适合研究外部弯矩的影响。 事实上，三维模型有很大的潜力，因为与二维模型相比，三维模型允许更真实的结构行为，尤其是在法兰孔和螺栓需要建模的情况下。此外，三维方法对于获得垫圈接触应力的真实圆周和径向分布至关重要，垫圈接触应力是控制泄漏的关键参数[2]。因此，本研究的目的是开发一个三维有限元模型（3D FEM），以评估弯曲荷载对螺栓法兰连接的机械和密封完整性的影响，并将3D FEM获得的数值结果与之前PVRC项目测试的螺栓接头获得的现有实验数据进行比较[3,4,9]。 第2部分:螺栓法兰接头的三维有限元建模和测量垫圈接触应力的传感器的开发:测量螺栓法兰接头中垫圈接触应力的传感器的开发法兰旋转产生的垫圈应力分布对螺栓法兰接头的泄漏行为有重大影响，然而，目前还没有可靠的实验技术来直接测量螺栓法兰接头中的垫片接触应力。已经生成了几个PVRC有限元模型，用于预测螺栓连接和法兰连接中的垫片应力分布[7,8,9]。然而，这些有限元模型的验证是基于间接参数的测量，如法兰旋转和残余螺栓载荷。 开发了一种特殊的法兰连接，用于测量传感器法兰下的径向应力变化。使用该传感器获得的实验结果将与PVRC项目98-04中开发的三维有限元模型获得的可用数值接触应力分布进行比较。

Part 1: 3D-Finite Modeling of Bolted Flanged Joints and Development of a Transducer for Measuring Gasket Contact Stress: 3D Finite Element Modeling of Bolted Flanged Joints Subjected to External Bending LoadsIn real life, bolted flanged joints can be subjected to external loads from many different sources including thermal expansion of piping and piping components, misalignments of pipe supports, and non-symmetrical thermal expansion of the joint components. In most of these cases bending moments are induced in the pipes and are transmitted to the flanges. For the design of bolted flanged joints, the effect of these moments must be accounted for as it can affect their mechanical and tightness behaviors. The use of the finite element technique for the analysis of bolted flanges subjected to non-symmetrical loadings is powerful and economical. This is particularly true for large dimension flanges for which experimental testing is very expensive and difficult to achieve. An attempt has been made in 1996 at TTRL [1] to develop a finite element model with non-axisymmetric loading using Fourier expansion to transform the three dimensional loading into a two dimensional one. The results obtained with this model were not satisfactory because the non-linearity of the bolted joint behavior was not accounted for. For non-symmetrical loading, the use of a three dimensional modeling of the joint components is certainly more appropriate to study the effect of external bending moments. In fact a three dimensional model has a great potential since it allows a more realistic behavior of the structure when compared to two dimensional model, particularly if the flange holes and the bolts need to be modeled. In addition, a three dimensional approach is essential to obtain a realistic circumferential and radial distribution of the gasket contact stress which is the key parameter that controls leakage [2]. The purpose of this research is therefore to develop a three dimensional finite element model (3D FEM) to evaluate the effect of bending loads on the mechanical and tightness integrity of bolted flanged connections, and to compare the numerical results obtained with the 3D FEM to existing experimental data obtained from bolted joints that were tested for previous PVRC projects [3, 4, 9].Part 2: 3D-Finite Modeling of Bolted Flanged Joints and Development of a Transducer for Measuring Gasket Contact Stress: Development of a Transducers for Measuring Gasket Contact Stress in Bolted Flanged JointsThe gasket stress distribution generated by flange rotation has a major impact on the leakage behavior of a bolted flanged joint, however there is currently no reliable experimental technique to directly measure the gasket contact stress in a bolted, flanged joint. Several PVRC finite element models have been generated to predict the gasket stress distribution [7, 8,9] in bolted, flanged connections. However, the validation of these FE models is based on the measurement of indirect parameters such as the flange rotation and the residual bolt loads. In this project, a special transducer, located in the flange beneath the gasket, to measure the radial variation of the contact stress developed in a bolted flanged connection has been developed and evaluated. The experimental results obtained with this transducer will be compared to the available numerical contact stress distributions obtained with the 3D-finite element model developed in PVRC project 98-04.