北京信息科技大学图书馆中庭喇叭形网壳结构建模与设计  

Structural Modeling and Design of BISTU Library Trumpet-Shaped Reticulated Shell Building

作　　者：李占伟 杨勇[1] 江洋 李婷[1] 耿海霞 Zhanwei Li;Yong Yang;Yang Jiang;Tang Li;Haixia Geng(Beijing Architectural Design and Research Institute Co.,Ltd.,Beijing 100045,China)

机构地区：[1]北京市建筑设计研究院有限公司,北京100045

出　　处：《钢结构（中英文）》2021年第5期33-39,共7页Steel Construction（Chinese & English）

摘　　要：北京信息科技大学图书馆中庭幕墙高25 m,两端粗中间细,形似喇叭,结构形式为单层钢结构网壳,构件采用矩形钢管。由于单层网壳结构非常纤薄,需要重点关注其稳定设计。以钢结构网壳的稳定问题为切入点,以全流程设计为主线,重点从方案比选、精准建模、二阶直接分析法的应用、边界条件等影响结构稳定的几个主要方面展开论述:1)通过改变环向约束构件的数量,将中庭钢结构分为3种网壳模型进行对比,并从中选出最优的结构模型。2)矩形管网壳结构的建模需要构建两个主轴的其中一个垂直于网壳曲面,常规的解决办法是参数化建模,不易操作。从实用角度出发,给出了用MIDAS结合RHINO软件对矩形管结构精准建模的简化方法。3)应用二阶直接分析法进行结构设计,需要模拟包含结构整体缺陷P-Δ0和构件缺陷P-δ0。整体缺陷P-Δ0的模拟可以采用将结构形态按第1阶屈曲模态调整的方法,一般通用有限元软件均很容易做到,构件缺陷可以用半个正弦波模拟,矩形管构件的缺陷需要指定方向,目前一般软件尚不能自动考虑构件缺陷形态和方向,这是应用二阶直接分析法的难点之一。为解决该问题,可以采用EXCEL对MIDAS数据文件进行处理。4)单层网壳结构一般对边界条件的自由度要求较高,采用已获得国家专利授权的一种新型网壳结构支座,该支座实现了约束水平位移和灵活释放竖向位移的效果。通过分析得到:1)由于环向箍的存在,三角形网格方案整体性最好。2)矩形管精准建模方法简单实用,便于设计人员操作。3)构件缺陷P-δ0建模方法,解决了现阶段软件不能自动实现构件缺陷建模的难点。4)新型专利支座很好地满足了模型边界条件对自由度的释放和约束的要求。The atrium of the BISTU library is 25 m high,with both ends thick and thin in the middle,shaped like a trumpet.The structural form is a single-layer reticulated steel structure,and the structural components are rectangular steel pipes.The single-layer reticulated shell structure is very thin,and needs to focus on its stable design.Taking the stability problem of a steel reticulated shell structure as the theme,and taking the whole process design as the main line.Discussed from several main aspects that affect the stability of the structure,mainly including structural form,modle,the application of second-order direct analysis method and boundary conditions.1)By changing the number of circumferential components,the atrium structure was divided into three models for comparison,and the optimal structural model was selected.2)The structural model of the rectangular pipe reticulated shell required one of the two main axes of the component to be perpendicular to the surface of the reticulated shell.The conventional solution was parametric modeling.From a practical point of view,the paper presented a simplified method of realizing accurate models with MIDAS software combined with RHINO Software.3)The application of the second-order direct analysis method for structural design requires the model to include P-Δ0 and P-δ0。P-Δ0 can adopt the method of adjusting the structure shape according to the first-order buckling mode,which can be done by general finite element software.Component defects can be simulated by half a sine wave,and the defects of rectangular tube component needs to be a specified direction.At present,general software cannot automatically consider the shape and direction of component defects.This is one of the difficulties in applying the second-order direct analysis method.To solve this problem,the paper used EXCEL to process MIDAS data files.4)The single-layer reticulated shell structure has higher requirements for the support.A new type of structural support has been introduced,which has obtained the

关 键 词：稳定 网壳 二阶直接分析 构件缺陷 支座 

分 类 号：TU392[建筑科学—结构工程]