【作者】 刘桂娥；

【导师】 钱才富；

【作者基本信息】 北京化工大学 ， 化工过程机械， 2007， 硕士

【摘要】 塔设备是化工生产中非常重要的设备之一，为满足工艺要求，需要在塔体上开大孔。大开孔会削弱塔体强度并会造成孔边应力集中，从而导致塔体承载能力的下降。另外，塔设备多为高径比非常大的薄壳设备，在风载荷、地震载荷作用下容易发生局部失稳。因此研究塔设备中的大开孔补强问题和塔体的失稳问题具有理论意义和实用价值。大开孔补强的研究：大开孔对壳体削弱程度与壳体的几何尺寸、开孔的形状与载荷及约束等因素密切相关，因此，对于大开孔的补强形式很难有一个统一的规定，以往大开孔补强问题的研究对象多为圆形或椭圆形开孔与接管。本文利用有限元法分析了圆柱形壳体矩形大开孔问题，研究了四种补强方法，指出增加接管壁厚或接管上设置加强筋能有效提高结构的承受内压的能力，但对提高整体结构的屈曲载荷效果不大。对塔设备失稳问题的研究：由于结构和载荷的复杂性，开大方孔塔的临界载荷很难用公式直接求解。本文采用有限元法，通过对筒体上不设加强筋和设加强筋两种形式的静力、稳定性进行分析发现，环向加强圈能有效提高结构承受外压载荷的能力，同时对结构承受侧向压的能力也有一定的提高，而竖向加强筋能明显提高结构承受侧向压力的能力，但对提高承受外压载荷的作用不是很明显。两者对由风、地震弯矩引起的应力分布都有一定的改善作用。更多还原

【Abstract】 Tower is one of the most important equipment in Petro-chemical engineering. Required by chemical process, large openings on the shell of the tower are inevitable, which weakens the strength of the tower and leads to stress concentration, and, as a result, decrease the loading-carrying capability of the tower. So study on the reinforcement of large openings and the buckling behavior of cylindrical shells with large openings is of theoretical and practical value.Study on reinforcement of large openings. Weakening of the large openings to shell is closely related to many factors, like the size of the shell, the shape of the openings, constrains, loads and so on. So it is hard to make a unified standard for different reinforcing methods, especially for large rectangular openings. In this thesis, FEA methods are employed to analyze a large rectangular opening in a cylindrical shell. Emphasis is placed on the effects of four reinforcing methods. It is found that strengthening ribs on nozzles well reduce stress concentration but are not effective in increasing the buckling loads of the shell. Similar results are reached for the effect of the nozzle thickness.Study on the buckling behavior of a cylindrical tower. Because of the complication in structure and loads, it is very hard to work out the buckling loads of shell structures with large rectangular openings by classical analytical method. By comparing the results of the static analysis and buckling analysis of the shell structures with and without stiffening rings, it is found that circle stiffening rings can greatly increase the buckling loads of external pressures, and they are also effective in raising the tower’s ability to undertake the lateral pressures produced by wind and seismic loadings. The vertical strengthening ribs, however, only have significant effects on the ability of. carrying the lateral pressures. Both of the two methods can improve the stress distribution induced by lateral pressures更多还原