【作者】 毋英俊；

【导师】 陈志华；

【作者基本信息】 天津大学 ， 结构工程， 2010， 博士

【摘要】 空间网格结构以格构的空间受力体跨越大跨度,造型优美、性能优越,经过多年的发展已经成为我国空间结构的主要形式之一。预应力钢结构通过布置施加预应力的钢拉索提高结构的承载力与刚度,经过多年的研究与工程实践,已经发展成以弦支结构体系为代表的完备体系。作为空间网格结构和预应力钢结构关键部件的拉索及与其相联系的节点不但对于结构的安全性与耐久性有着十分重要的影响而且节点对于拉索的约束形式和程度,即拉索是否可在节点处滑动对于整个结构的受力状况和施工方式都有重大影响。节点处可滑动索体系是空间网格结构、预应力钢结构和相关施工过程中业已存在或可以采用的张力体系形式,有必要对该体系进行系统的研究。在拉格朗日描述下以等参单元形式,通过格林应变和第二克希荷夫应力,利用虚功原理重新推导了连续折线索单元的刚度矩阵,同时也给出了相应的质量矩阵和荷载列阵的表达方式,并针对在ABAQUS程序中实现该单元算法的过程给出了经验方法并对单元适用范围、显示方法和调试策略提出建议。利用连续折线索单元,分析了天津保税区商务交流中心大堂屋盖弦支穹顶在全跨、半跨荷载作用下,环索采用连续可滑动索和间断不可滑动索模型的静力、稳定性能,以及两种环索模型分别在多遇地震和罕遇地震下的地震时程响应。结果表明,全跨对称荷载下环索滑动与否对结构影响很小,半跨荷载下可滑动环索应力更为均匀,地震作用下环索滑动模型响应略大。利用张拉自升攀达穹顶工程资料,结合连续折线索单元算法,建立了某斗牛场张拉自升攀达穹顶结构模型,模拟了其提升施工的全过程,分析了结构各部分位移,应力等信息,发现了张拉位移与结构提升位移的线性关系和位移放大效应,理清了该结构体系的规律与脉络,证明了连续折线索单元的可靠性,同时实践了张拉自升攀达结构体系的设计与分析过程。依据弦支穹顶结构下部索杆体系采用可滑动索体系的构想,提出了可实现环索滑动的弦支穹顶滚动式张拉索撑杆下节点的构造概念,并给出了单体式和压板式两种可滑动节点设计方案。按照可滑动节点的概念和思路设计并制造了实物模型节点,并对其进行了有限元模拟和试验研究。试验证明可滑动节点可有效减小拉索与节点间的摩擦,在使用四氟乙烯环的情况下预应力损失可以控制在10%左右,节点应力分布有限元分析结果与试验结果具有相同的趋势。将滑动式撑杆下节点概念应用于实际工程之中,进行了节点深化设计,并对山东茌平体育馆弦支穹顶工程中典型的三个铸钢撑杆下节点进行了有限元分析,印证了节点设计的合理性和安全性。更多还原

【Abstract】 Spatial grid structure has become one of the major forms of spatial structure inChina, because of its elegant appearance and excellent performance. In virtue of yearsof research and project practice, pre-stressed steel structure which improves criticalloading capability and stiffness by distributing tensioned cable has been developedinto an exhaustive structure system represented by a cable-supported structure system.Being a critical part of both spatial grid structure and pre-stressed steel structure,cable together with its connected joints plays a crucial role in whatever security orduration for pre-stressed structure. Besides, restraint forms and extents the cable hasbeen restrained imposed by the nodes, that is, whether cables can slide at joints posessignificant influences on load conditions for overall structure and construction ways.It is argued that the tensioned system including sliding cables is a currently-existing orelse potentially-applied form of tensioned system in pre-stressed steel structures andcorrelative construction courses so systematic researches were necessary.Beneath the Lagrange formulation, stiffness matrix of sliding cable element wasre-deduced using virtue work theory through Green strain and PK2 stress in theisoparametric element form. Corresponding mass matrix and expressions of loadvector were derived simultaneously. Furthermore, experience-based approaches to thealgorithms serving to realize the very element in ABAQUS programming andapplicability, display, strategyof debugging were addressed.Tianjin Free Trade Zone business communication, whose suspendome roof ofhall was analyzed from the following respects under all-span and half-span load case:static , nonlinear buckling character and time-history responses under frequentearthquake and rare earthquake region. Both sliding cable element and discontinuouscable element are distributed in models for compare. It shows that whether loop cableslides influence little under all span symmetric load, while cable stress is moreuniform among different cable segment in continuous loop cable model thandiscontinuous one. Seismal response is more significant in continuous loop cablemodel under both frequent earthquake and rare earthquake region.In combination with sliding cable element algorithm, using the information of new type pantadome system, a tension-self-ascending pantadome system structuremodel for a specific bullring was established. Complete ascending process wassimulated. Information such as displacement and stress for each part of it wereanalyzed. It is noticed that the relation of cable tension displacement and structureascending displacement is linear and the latter one magnifies the former one. Venationand regulations of self-ascending structure system were clearly displayed and that thereliability of continuously sliding cable element was testified. Meanwhile, design andanalysis progress of self-ascending pantadome system was carried out.According to the idea of applying cable-strut tensegric system including slidingcable to suspendome, a concept concerning on a realizable cable-strut joint insuspendome through which loop cable can slide freelywas advanced. And its two newproposals forms of joint single-body joint and pressure-plate joint were given.Practicality model joint were designed and produced. Finite element simultaneous andexperiment researches were carried out. The experiment shows that the slidingcable-strut joint can reduce the friction between cable and joint. The loss of prestressin cable can only be about 10% when 4F ring is used. The trend of stress distributionin experiment is similar with FEM analysis.Concept of sliding cable-strut joint was applied in practical projects. Detaileddesigns of joints were devoted. Finite element analysis was used aiming at threetypical cast steel cable-strut joints in Chi Ping Gymnasium suspendome to verify therationalityand securityof nodes design.更多还原