非圆截面法兰连接结构分析

发布时间：2018-05-05 02:40

本文选题：非圆法兰 + 连接结构　；参考：《河北工业大学》2011年硕士论文

【摘要】：法兰结构是石油化工、天然气、机械动力、能源等工业领域应用最广泛的可拆连接形式。随着工业技术的不断发展和工艺要求的不断增多,非圆压力容器的应用场合也在不断增大,随之出现了一些特殊的法兰密封和紧固方式。目前,非圆法兰结构的分析计算方法还不完善,本文以压力油箱为研究对象,利用有限元数值方法,对非圆截面法兰连接结构进行了分析计算。 1、利用ANSYS有限元软件建立O形橡胶密封圈的二维有限元模型,在预紧和介质压力两种工况下,考虑橡胶密封圈的材料非线性、几何非线性和接触非线性行为,得出橡胶圈的最大Von Mises应力分布、接触变形、有效接触宽度以及接触面上接触压力分布规律。计算表明,随着压力的增大,接触面上的最大接触压力随之增大,且最大接触压力始终大于介质压力,满足密封条件。得到了O形橡胶密封圈的合理压缩率,为该结构中螺栓预紧力的确定提供了依据。 2、利用ANSYS有限元软件的APDL参数化语言建立非圆截面螺栓法兰连接结构的三维非线性有限元模型,用约束方程和MPC技术实现不同疏密单元之间的连接及绑定接触,考虑了O形橡胶密封圈与沟槽之间以及螺母和平盖之间接触行为的非线性。在预紧工况下,得出了O形橡胶密封圈的应力分布状态以及接触面上接触压力的分布状况,分析了密封圈沿周向的应力变化规律,该规律受螺栓分布以及连接结构的刚度的影响。在操作工况下,从整体角度有效地分析了非圆截面法兰连接结构系统中各个连接件的应力分布及其变形情况,并对螺栓进行应力强度评定,从而得到螺栓群沿周向的应力分布情况,针对这种非圆结构提出了螺栓应力强度的评定条件。对平盖、法兰和筒体结构的厚度方向和周向进行应力路径评定,发现周向的应力分布与结构刚度有关。
[Abstract]:Flange structure is the most widely used detachable connection in petrochemical, natural gas, mechanical power and energy industries. With the development of industrial technology and the increasing of process requirements, the application of non-circular pressure vessels is also increasing, and some special flange sealing and fastening methods appear. At present, the analysis and calculation method of non-circular flange structure is not perfect. In this paper, the finite element numerical method is used to analyze and calculate the non-circular section flange connection structure, taking the pressure tank as the research object. 1. The two-dimensional finite element model of O-shaped rubber seal ring is established by using ANSYS finite element software. The material, geometric and contact nonlinear behaviors of rubber sealing ring are considered under two working conditions of pre-tightening and medium pressure. The maximum Von Mises stress distribution, contact deformation, effective contact width and contact pressure distribution on the contact surface are obtained. The calculation shows that the maximum contact pressure on the contact surface increases with the increase of the pressure, and the maximum contact pressure is always greater than the medium pressure, which satisfies the sealing condition. The reasonable compression ratio of O-shaped rubber seal ring is obtained, which provides the basis for the determination of bolt pretightening force in this structure. 2. Using the APDL parameterization language of ANSYS finite element software, the three-dimensional nonlinear finite element model of bolted flange connection structure with non-circular section is established. The connection and binding contact between different thinning elements are realized by using constraint equation and MPC technology. The nonlinearity of contact behavior between O-rubber seal ring and groove and between nut and cover is considered. The stress distribution state of O-shaped rubber seal ring and the distribution of contact pressure on the contact surface are obtained under pre-tightening condition, and the law of stress variation along the circumferential direction of sealing ring is analyzed. This rule is affected by the distribution of bolts and the stiffness of the connection structure. Under the operation condition, the stress distribution and deformation of the joints in the non-circular section flange connection system are analyzed effectively from the whole angle, and the stress intensity of the bolt is evaluated. The stress distribution of bolt group along the circumference is obtained, and the evaluation condition of bolt stress strength is put forward for this kind of non-circular structure. The stress paths of the thickness direction and circumferential direction of the flat cover flange and cylinder structure are evaluated and it is found that the stress distribution in the circumferential direction is related to the stiffness of the structure.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH136

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