长沙Live中庭屋盖大跨空间自由曲面网壳结构设计

长沙LIVE中庭自由曲面屋盖跨越支承在下部4个结构单体上,中间局部为可开合式屋面,二次膜结构生根于主体结构之上,中庭屋盖采用大跨度单层网壳结构。介绍了结构选型及固定铰支座与滑动铰支座的合理设置方法;根据当地自然条件和风洞实验报告进行屋盖的风荷载取值;通过有限元软件MIDAS/Gen对网壳结构进行了静力和整体稳定性分析,并且将网壳与下部混凝土结构协同工作,比较自振周期、位移、支座反力来分析下部结构对网壳结构受力的影响;同时通过有限元模型对节点设计承载力和刚度进行了分析,网壳的各项计算结果均满足要求。此外,在施工过程中进行了变形监测,监测数值均在设计计算范围内。     

商业建筑中庭空间单层网壳结构效果分析——以湖南长沙中海环宇城为例

文章以中庭的发展为切入点,重点提出商业建筑的中庭空间,简述其空间效果,再进一步探索中庭结构中的单层网壳结构,并以湖南省长沙市中海环宇城为例,通过对其中不同商业空间所产生的中庭给顾客带来的不同体验进行分析,简述单层网壳结构的在商业空间中体现的独特性。     

预应力钢网壳的某些静力性能研究

在网壳结构下部用预应力钢索施加与外荷载作用下方向相反的力，对改善网壳结构的受力状态，提高结构承载能力，增强结构的整体刚度、节约钢材、降低造价等有利，本文进行了预应力短程线型钢网壳计算理论的研究，给出了预应力索单元的刚度矩陈，编制了空间杆系有限无理论的预应力网壳五阶段全过程设计的静力分析程序，结合已完工的攀枝花体育馆屋盖网壳结构的工程实例，探讨了短程线型钢网壳的自重、拉索预应力和设计荷载作用下结构的内力及位移的分布规律、索力的优选、预应力损失以及支座约束变化对网壳内力和位移的影响，还对比了风壳在不同预应力张拉顺序及有无预应力时的计算结果。     

基于组合-分层壳元理论薄壁预应力混凝土结构的力学响应

基于组合-分层壳单元,建立薄壁预应力混凝土结构的计算模型,并对其力学行为进行分析。首先引入壳元理论,对薄壁结构进行壳元离散。并对壳元中的混凝土应用分层理论描述,对壳元中的钢筋单元采用大变形杆单元模拟。根据钢筋和混凝土在壳元内的位移协调条件,推导了整体转换矩阵后,将两者组合成一个单元,同时基于虚功原理推导了钢筋对组合壳元整体刚度矩阵的贡献。算例分析表明,本文方法的计算结果与已有的试验结果吻合良好,本文研究的组合壳元模型能适应钢筋的任意布置方式,能较全面地反映混凝土内钢筋的力学效应,数值计算稳定性良好,弥补了商用有限元软件非线性计算稳定性较差这一缺点。组合-分层壳元法为薄壁预应力混凝土结构提供了一种有效的分析方法。     

施威德勒球面网壳的稳定性分析

稳定性分析是网壳结构尤其是单层网壳结构设计中的关键问题.本文论述了网壳结构稳定分析的理论和方法,利用大型通用有限元分析程序ANSYS对施威德勒单层球面网壳进行建模及求解分析,并得出了一些有用的结论.     

新型宽扁平箱梁结构分析程序和使用界面例析

以城市宽扁平箱梁为对象,根据其变形特点,构建了新型的亚参元板壳单元,在此基础上开发了一种兼顾操作方便性和计算精度的预应力混凝土宽扁平箱梁结构分析程序和使用界面。     

关于SAP-6的载荷工况与组合

一、概述 SAP—6结构静动力线性有限元分析程序是美国加洲大学伯克利分校威尔逊教授主持下完成的一个大型结构分析程序。其中包含了杆、梁、管,平面、实体、板、壳、轴对称、边界元、空白元以及读入刚度元等10多种工程中常见的单元。对于结构载荷的     

板锥网索结构的超级有限元分析

板锥网索结构是一种新型的组合网壳。本文在对这类结构有限元法分析的基础上，根据板锥网壳结构的构成特点，应用超级元分析的基本思想，对这类结构进行了分析，给出了这类结构超级元分析基本公式。算例分析结果表明：与一般有限元法相比，超级元法大大节省了计算量，结点自由度可降二个数量级，具分析结果和有限元法基基吻合，为这 类大跨空间结构应用微机分析提供了一种新的方法。     

柱面网壳结构动力稳定性分析

利用ANSYS软件中的动力分析程序,研究了柱面网壳结构在地震作用下失稳时,静荷载和杆件局部失稳对结构整体失稳的影响程度,并通过计算分析,得出了一些有益的结论。     

网壳结构的非线性分析

结构非线性分析程序可用于分析梁、杆组成的结构,并可进行线性、几何非线性稳定分析。本文主要介绍该程序的分析理论、程序前后处理及基本功能,并采用典型算例进行分析验证。结果表明,该程序具有很好的分析效率及较强的适用性。程序对大小相同、采用同种材料的单层网壳和局部双层网壳进行计算,发现两者在稳定性方面的一些特性。     

Vibration of a thin-walled carbon fibre corrugated circular cylinder under external water pressure

The paper reports on a theoretical and an experimental investigation carried out on a thin-walled corrugated carbon fibre circular cylinder in air and also under external water pressure. This corrugated circular cylinder was invented by Ross in 1987.The theoretical investigation was carried out using the finite element analysis to model both the structure and the fluid. The theoretical investigation used two different programs, one of which was the giant computer program ANSYS and the other was an in-house program developed by Ross and Little. For the shell structure, the ANSYS program used two different doubly curved thin-walled shell elements, while the in-house program used a simpler axisymmetric thin-walled shell element. This axisymmetric element allowed a sinusoidal variation of the displacements in the circumferential direction, thus, decreasing preparation and computational time. Agreement between the different finite elements was found to be quite good. The investigation also found that there was good correlation between experiment and theory for the in-house software, but was a little disappointing when using ANSYS. Errors may, however, have occurred with the experimental results, as the model was hand-made and neither its geometry nor its material properties were perfect. It was found particularly encouraging for the in-house software to give better results than ANSYS, as the in-house software only took a few hours to set up the computer model, and a few seconds to analyse the vessel, whereas the ANSYS software took several weeks to set up the computer model, and several minutes to analyse the shell. The ANSYS software, however, did have the advantage in producing excellent graphical displays in both the pre-processing and post-processing modes.     

An AI-based shell for linking thermal and form-making considerations

Over the past few years, our team has developed several computer-based models in the areas of architectural form-making and thermal analysis. These programs were designed to deal with specific problems and use a range of techniques including machine vision, knowledge-based systems, and artificial intelligence techniques. Recently, a project that integrates these systems was initiated. Its objective is to design an intelligent computer shell that forms the basis for this integration in the domain of architecture. The paper discusses the development of the shell and its use to analyze and study architectural form and its determinants. The shell accommodates modules that link the morphological structure of architectural design with more of its determinants (e.g., structural, acoustical, and lighting considerations, as well as code requirements). The paper presents and discusses the background of the shell, its structure, its methods of knowledge representation, and an example of its use.     

上海科技馆网壳结构分析

针对上海科技馆中部大堂的巨型椭球体网壳结构 ,介绍了网壳结构的选型 ,并比较了在刚接、铰接和弹性支承条件下 ,钢、铝网壳结构方案在竖向荷载、温度荷载、地震作用下的受力特性。为网壳结构非线性分析提供了依据     

大梅沙酒店大堂网壳结构稳定性分析

稳定性分析在单层网壳结构设计中非常重要。本文对大梅沙酒店大堂单层网壳的稳定性进行了系统的分析。根据静力计算的结果确定杆件截面,并运用有限元分析方法,对结构进行屈曲模态分析,预测出结构屈曲荷载的上限,在考虑初始缺陷、几何非线性和材料非线性的影响下,进行荷载—位移全过程分析,从而确定了结构的极限荷载。结果表明,单层网壳稳定性分析时,应该同时考虑几何非线性和材料非线性。     

Analysis of multiple stiffened barrel shell structures by strain-based finite elements

In this paper strain-based rectangular cylindrical shell and curved arch finite elements are coupled to straight beam finite elements to analyse multiple stiffened barrel shell structures. The first two finite elements are based on assumed strains rather than displacement fields. The results obtained with this analysis are successfully compared with values derived from several commercial computer codes.     

浅谈北京某大厦网壳结构安装施工工艺

对北京某大厦中庭屋盖三向网格单层柱面网壳结构的安装施工流程、施工准备工作进行了分析,重点阐述了累积滑移的施工步骤,说明了累积滑移施工是网壳工程安装过程中的重中之重,合理的滑移设备及合理的施工工艺对整个安装过程起着至关重要的作用。     

单点连续冲击荷载下单层球面网壳结构失效模式研究

为研究单点连续冲击荷载作用下单层球面网壳结构的失效模式,应用通用有限元软件ANSYS LS-DYNA建立了40m跨度,四种不同矢跨比的K8型单层球面网壳结构有限元模型。通过分析单层球面网壳结构在单点连续冲击荷载作用下失效全过程的冲击荷载、能量转化和杆件变形特点,总结归纳出单层球面网壳结构在单点连续冲击荷载作用下的五种失效模式:网壳局部凹陷、网壳局部凹陷时杆件剪切破坏、网壳整体塌陷、网壳整体塌陷时杆件剪切破坏、杆件剪切破坏。对五种失效模式进行了全过程研究分析,明确了单层球面网壳结构在单点连续冲击全过程中肋杆、环杆、斜杆的破坏形式和能量传递与转化特点。     

合肥CBD中央广场抗震性能分析

合肥CBD中央广场工程采用了大底盘多塔楼的复杂结构形式 ,地震反应复杂 ,在设计过程中采用了SATWE程序和SAP2 0 0 0程序进行分析 ,并根据计算结果调整了设计方案 ,力争改善结构的抗震性能 ,满足规范的相关要求。本文探讨了复杂结构抗震分析中一些问题 ,并结合工程归纳为一些大底盘多塔楼复杂结构改善性能的措施。     

A parametric finite element study of cracked plates and shells

The overall behavior of plates and shells as affected by the presence of a through crack in the elastic range has been studied. Due attention has been paid to finite element modeling aspects of the problem. Forty different cracked plate and shell FE models have been generated and analyzed by a special computer program developed for the purpose of this study. The significance of various parameters such as the order of mesh refining at the crack tip, the effect of boundary conditions, Poisson's ratio, crack length and shell curvature are studied. FE model consisting of isoparametric 4-noded shell elements moderately refined at the crack tip predicted the overall stress and displacement field with acceptable precision.     

Buckling analysis of a cooling tower shell with measured and theoretically-modelled imperfections

Geometrical imperfections were measured using photogrammetric techniques on an existing reinforced concrete cooling tower shell. The imperfections, related to the radii of such a real shell, were used as input data to create a real shape of the cooling tower. Numerical analysis was carried out for three models: (P) perfect shell of revolution, (M) shell with measured imperfections, (T) shell with a theoretical imperfection corresponding to the primary buckling mode under dead load. The buckling analysis was related to the linearized eigenvalue problem of elastic shells. The shell midsurface was approximated by eight-node quadrilateral isoparametric finite elements. Computations were carried out using the ANKA computer code. Critical values of the load parameter enable confirmation of a partial correlation between existing imperfections and buckling modes under dead load. The most disadvantageous direction of the wind load application on the real shell was found, in order to evaluate the decrease in the load-carrying capacity of the cooling tower shell against buckling. Theoretically modelled imperfections give rather unrealistic values of buckling loads of the real shell.