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基于气泡理论的新型多面体空间刚架系由类WP多面体单元经组合、阵列、旋转、切割而生成,它有别于传统空间结构由单元体简单组合而成。因此,基本单元的形状与尺寸、旋转轴、旋转角度、切割面位置等都是影响整体结构几何构成的重要参数,也是结构几何构成优化的主要内容。通过对这些参数的分析比较,本文提出新型多面体空间刚架几何构成的优化准则,提出最优切割面和可行切割面的重要概念,从而为建立各种高效合理、同时充分满足建筑效果的结构构成提供理论依据与可行方法。在此基础上,结合国家游泳中心“水立方”结构,具体说明了本文提出的优化原则与方法在实际工程中的应用与效果。本文研究揭示了多面体空间刚架结构区别于传统结构的一个重要特点———建筑尺寸由结构的几何构成所确定。 相似文献
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介绍了一种自应力自平衡的张力单元结构,这种单元结构由5杆8索构成,文中证明了它的几何稳定性,分析了结构性能与几何外形参数之间的关系,进而构造了一种由此类单元组合而成的平板网架。 相似文献
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张拉整体体系与多面体几何 总被引:4,自引:0,他引:4
张拉整体体系是40多年来发展起来的一种新型空间结构体系。拓扑和形态学是张拉整体体系的主要内客,而多面体几何构成了拓扑和形态学的基础。本文在研究多面体几何的基础上,分析了张拉整体单元体与多面体之间的关系,并探索了张拉整体体系几何法的找形分析。 相似文献
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基于气泡理论的多面体空间刚架是一种全新的空间结构,具有重复性高、汇交杆件少、节点种类少,结构承载、抗震、延性好等特点,在国家游泳中心“水立方”结构中得以应用。这种新型结构的基本单元是气泡理论中对三维空间进行有效填充的多面体。本文提出了新型多面体空间刚架结构中的基本单元———类Weaire-Phelan多面体单元,并通过图形解析和数学解析两种方法研究基本单元的几何构成,揭示了该类单元的重要特征———其基本形状仅由一个独立参数所控制,可定义其为形状控制参数c,并进一步揭示了多面体空间刚架中c的合理取值范围以及c和空间刚架总杆长及杆长种数的关系。这些研究成果为这一新型结构的几何构成奠定了理论基础。 相似文献
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B. Shekastehband 《钢结构国际杂志》2017,17(3):1049-1058
Tensegrity systems as kinematically and statically indeterminate pin-jointed systems are characterized by mechanisms and self-stress states. Taking into account the unilateral rigidity of cables may cause other mechanisms (unilateral) rather than bilateral infinitesimal mechanisms to be produced. Two numerical methods are presented for determining of bilateral mechanisms in tensegrity structures which are based on the geometrical characteristics and positive-definiteness of the tangent stiffness matrix, respectively. These methods allows distinction between first-order and higher order mechanisms. A numerical method is submitted for determining the unilateral mechanisms of these systems which uses the basis of the self-stress states for identifying prestressed and non-prestressed cable elements. 相似文献
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索承网壳结构是由单层球面网壳和去掉上层索的张拉整体结构组成的一种合理的新型杂交空间结构。选用梁元、杆元和索元的组合有限元模型,采用分块Lanczos法,针对一实际工程,通过改变结构参数、几何参数等诸多因素,较系统地研究了肋环型索承网壳结构的动力特性及抗震、抗风性能,对工程应用有一定参考价值。 相似文献
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预应力全索系整体张拉结构是具有“内部没有压杆的全索系拉杆海洋”特点的结构体系,该结构体系结构稳定承载力和变形性能是工程设计的关键。为研究全索系整体张拉结构的弹塑性发展规律,进行了基于材料非线性和几何非线性的结构承载全过程分析,得到典型单元荷载-应力、关键节点荷载-竖向位移全过程曲线。分析结果表明:建议全索系整体张拉结构索构件在弹性阶段的应力比应小于0.40,内环索竖向变形应小于悬挑跨度的1/40~1/50。全索系整体张拉结构的屈服荷载系数及延性性能高于有钢压杆的预应力钢结构体系;增大预应力度是改善谷索排雪水功能的有效措施之一。 相似文献
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B. Shekastehband 《钢结构国际杂志》2017,17(3):1115-1129
Tensegrity systems are composed of any given set of cables connected to a set of struts in which cables connectivity must be able to stabilize the configuration. In the present study, the collapse mechanisms of single curvature tensegrity systems was investigated by carrying out nonlinear collapse analyses using finite element method. Having verified the finite element modeling with the experimental results, several different collapse analyses have been undertaken in order to examine the instability behavior of the single curvature tensegrity systems. Consequently, the different collapse mechanisms of this type of tensegrity systems have been determined. In addition, the effects of the self-stress level, and the effects of the post-buckling response of the struts and the post-yield response of the cables have been investigated. Based on the obtained results, some important conclusions have been drawn regarding the instability behavior of these tensegrity systems. 相似文献
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尽管艺术家和结构工程师的工作目的有很大的区别,但他们的工作过程却有着相同的特征,这主要体现在初步设计阶段。而且艺术家在某些新型结构领域往往走在前列,尤其是在张拉整体这一领域。本文对这一方面进行了阐述,从艺术和结构工程、艺术家和结构工程师之间关系出发,逐渐形成了与张拉整体体系这一结构形态学相关的某些主要特征。第3节对已经实现的或者计划中的张拉整体体系工程进行了介绍。 相似文献
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新式CT型索结构的研究 总被引:6,自引:1,他引:5
CT型(Compression-Tensegrity)索结构(简称CT结构)是在研究了张拉整体(Tensegrity)结构(简称T结构)优缺点的基础上开发的一种新型索结构。它保留了T结构的优点,结构效率高于T结构,材料用量低于T结构,节点构造易实现,施工方法简单,屋面系统选型范围宽,造价较低。此结构属线性时不变系统。力学分析和结构设计较方便,是一种值得推广的结构形式。 相似文献
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Tensegrity structures are spatial, reticulate and lightweight systems composed of struts and cables. Stability is provided by a self-stress state between tensioned and compressed elements. Tensegrities have received interest among scientists and engineers in fields such as architecture, civil and aerospace engineering. Flexibility and ease of tuning make these systems attractive for controllable and adaptive structures. However, tensegrities are often prone to difficulties associated with meeting serviceability criteria and with providing adequate damage tolerance when used as civil engineering structures. This paper extends research on active control of tensegrity structures to study self-repair of a tensegrity pedestrian bridge that is damaged. Self-repair is intended to meet safety and serviceability requirements in case of cable damage in the pedestrian bridge. Intelligent control methodologies that implement stochastic search with active member grouping are proposed. Case studies for several damage scenarios are presented to show the effectiveness of the methodology. Results from simulated damage scenarios show that self-repair can be successfully performed with a minimum number of active members leading to a reduction in control complexity. 相似文献
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为解决指定节点坐标下张拉整体结构拓扑形态问题,提出一种将关联矩阵编码后组成方案矩阵的拓扑找形方法.基于张拉整体结构形态分析理论,以各节点连接构件的数量为约束指标,通过合理地选取构成方案矩阵中的若干元素以确定各单元所在的空间位置,由此构建0,-1整数变量与结构体系几何稳定之间的关系,结合稳定性判定条件以实现张拉整体结构的... 相似文献