Performance Analysis And Optimization Of Flange Bolt Joint Under The Influence Of Inhomogeneous Temperature Field

The performance of bolt joint is a key part of joint study for flange and pipe, it is more susceptible to fatigue due to the influence of internal temperature fluctuations, pressure and other factors, so the study of high-temperature flange bolt joint is one of the current research focus. The performance of flange bolt joint was discussed in this thesis, using the method of finite element analysis and experimental study, and two schemes of joint parameters was compared, under the influence of inhomogeneous temperature field. A three-dimensional mechanical model and transcalent model of flange bolt joint were built, using the finite element analysis software ANSYS, and the inhomogeneous temperature field, stress field and coupling field was simulated. Based on the orthogonal text, taken stress of bolts as the index, two schemes bolt system, disc spring and sleeve, were studied, and the least fluctuation parameters of bolt stress of disc spring and sleeve was selected in the experimental conditions. The primary contents were as follows:1. A three-dimensional mechanical model and transcalent model of flange bolt joint were built, considering the nonlinearity of gasket and contact problem.2. The inhomogeneous temperature field, stress field and coupling field of flange bolt joint system was simulated and analysisd using the ANSYS software, and the distribution of inhomogeneous temperature field, stress field and coupling field was obtained, the behaviour of flange bolt and gasket was analysed under the influence of inhomogeneous temperature field, these analyses had guiding significance for the parameter optimization of flange bolt joint.3. The stress distribution of bolts and gaskets of two schemes, disc spring and sleeve, was simulated and analysed using the ANSYS software, the positive effects was indicated to bolt joint and gasket seal in two kinds of schemes.4. The scheme of least fluctuation of bolt stress was selected by the numerical simulation of ANSYS.5. Based on the orthogonal text, taken stress of bolts as the index, the bolt system of two schemes, disc spring and sleeve, were studied, the least fluctuation parameters of bolt stress of disc spring and sleeve was selected, and two schemes was compared, the optimal parameters was elected in the experimental conditions.