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对电除尘器壳体顶梁提出了一种优化设计思路:即将保温层与原壳体小顶梁组合成一个桁架梁系,以增加梁系的整体截面高度,使桁架梁系的抗弯承载能力比原壳体小顶梁大幅提高,从而可以增大顶梁跨度,将两个小跨顶梁做成一个大跨桁架梁系,撤除原先的隔墙,以节省钢材。为此,采用一维梁杆结构体系计算方法和壳单元有限元方法对大跨桁架梁系的设计方案和内力计算方法进行研究,并着重用壳单元有限元方法对下弦箱形构件的承载性能进行研究,提出大跨桁架梁系的构件截面初选方法、优化构形方案以及内力计算方法,得到下弦箱形构件支承加劲肋端面承压计算方法、敏感的局部屈曲形式、最不利的初始几何缺陷模态,并对其横向加劲肋尺寸和纵向加劲肋高度位置提出优化建议。
An optimization design idea is proposed for the roof beam of electrostatic precipitator: the insulation layer and the small roof beam of the original shell are combined into a truss beam system to increase the overall cross-section height of the beam system so that the flexural bearing capacity of the truss beam system Capability than the original small cap roof substantially increased, which can increase the span beam, the two small span of the roof beam made of a large span beam, remove the original wall to save steel. Therefore, the design method and internal force calculation method of long-span truss girder system are studied by using the calculation method of one-dimensional beam structure system and the finite element method of shell element. The bearing capacity of the lower box element with the shell element finite element method is emphasized. The method of initial selection of component cross-section, optimization of configuration scheme and internal force calculation method of long-span truss girder system are proposed. The calculation method of bearing pressure on the end face of stiffener in lower chord box is obtained. The sensitive local buckling mode, the most unfavorable initial geometry Defect modes, and give suggestions on the optimization of transverse stiffener size and longitudinal stiffener height.