海洋贝类仿生建筑的结构形体研究

利用仿生学原理,借鉴深海扇贝形外壳的结构形式,提出了一种新型的网壳结构-扇贝形网壳结构,这种结构的表面呈波浪形,其受力特征与折板结构相似,具有形态优美、结构受力合理、用材省等优点.文中还提出这种新型网壳结构在建筑设计中的几种应用方法,并用CAD技术进行了结构建模.     

新型折板网壳结构特性及关键技术研究

折板网壳结构是一种新型的结构形式,兼具了空间桁架结构与空间网壳的优点。重点介绍了该结构在分析与设计中的关键问题:结构体系的布置与力学特性;荷载的安全取值以及构件合理计算长度系数的确定;利用弹塑性方法分析其稳定性、极限承载力以及塑性发展规律以说明折板网壳结构优异的力学承载性能;对复杂套钢管节点进行弹塑性分析。分析方法和结果可供类似结构的设计、分析参考。     

Design and compilation of specifications for a modular‐prefabricated high‐rise steel frame structure with diagonal braces. Part I: Integral structural design

Prefabricated steel structures have certain obvious advantages, that is, rapid construction, industrial production, and environmental protection. Although prefabricated structures have been applied in a number of countries in the world, in most cases, these structures are suitable only for low‐rise buildings, and their applications in high‐rise buildings are nota\bly rare. This paper proposes a new type of prefabricated steel structure called the modular‐prefabricated high‐rise steel frame structure with diagonal braces. Based on the T30 building, which is a hotel building with 30 storeys above the ground, the mechanical properties, failure mode, failure mechanism, and elastic–plastic development laws of the structure were studied via elastic and elastic–plastic design and analyses under various load cases and combinations. The analysis of the internal force and displacement response with frequent earthquakes was performed using the response spectrum and elastic time‐history methods, and an analysis under rare earthquakes is performed via static elastic–plastic pushover analysis. This paper summarizes the elastic and elastic–plastic structural design methods and process. This study provides important references for the design of this kind of modular‐prefabricated high‐rise steel structure, and the design method has been compiled into a design specification named Technical Specifications for Prefabricated Steel Frame Structure with Diagonal Bracing Joints.     

Performance‐based plastic design and collapse assessment of diagrid structure fused with shear link

A diagrid structure fused with shear link (DSSL) is an innovative earthquake resilient structural system. The DSSL combines the steel diagrid structural system with shear links to dissipate the earthquake energy with the goal to minimize structural repair and downtime after strong earthquake shaking. The SLs are placed between diamond‐shaped grid units and decoupled from the gravity system. To facilitate the design of the proposed DSSL system, the performance‐based plastic design (PBPD) procedure is extended to design a prototype building utilizing DSSL. Detailed finite element model is developed to simulate the non‐linear dynamic response of the structure under a range of earthquake shaking intensities. The results of non‐linear dynamic analyses show that the DSSL has excellent seismic performance and can be efficiently designed using PBPD. Lastly, detailed collapse risk assessment of the prototype building is performed using the FEMA‐P695 methodology. The result shows that the PBPD‐designed DSSL has adequate margin against collapse. Hence, it can be used as an effective seismic force resisting system.     

Design and specification compilation of a modular‐prefabricated high‐rise steel frame structure with diagonal braces part II: Elastic–plastic time‐history analysis and joint design

The use of modular‐prefabricated steel structures has distinct advantages, such as rapid construction, industrial production, and environmental protection. Although this type of structure has been extensively employed around the world, it is primarily used for low‐rise buildings; its application in high‐rise buildings is limited. This paper proposes a new type of modular‐prefabricated high‐rise steel frame structure with diagonal braces. An elastic–plastic time‐history analysis of a 30‐storey building during rare earthquakes was performed. The base shear, storey drift, stress, damage characteristics, and other performances of the structure were investigated. According to the mechanism analysis, finite element simulation, and model test, the formulas for the elastic and elastic–plastic design of the truss–column connection, column–column flange connection, and diagonal brace–truss connection are proposed in this paper. The control parameters for the structural design are also discussed. This study provides an important reference for the research and design of this type of modular‐prefabricated high‐rise steel structure. The design method has been compiled into a design specification named Technical Specifications for Prefabricated Steel Frame Structure with Diagonal Bracing Joints, which is unique for this type of structure.     

Performance‐based plastic design method for tall hybrid coupled walls

The research presented herein involves a performance‐based design method for a tall hybrid coupled wall (HCW) system. For this study, HCW structures were designed with a performance‐based plastic design (PBPD) method. This approach directly accounts for inelastic structural behavior and considers design lateral force distribution at ultimate limit state. The design concept uses a pre‐selected target drift and yield mechanism as key performance limit states. The yield mechanism consists of shear yielding in the coupling beams and flexural yielding of reinforced concrete walls at the bases. HCW structures with varying heights and coupling ratios (CRs) were designed and subjected to a series of nonlinear dynamic analyses. The results indicated that the CR strongly influences the response of the structure. The structures could also be under‐designed when the inelastic distribution of lateral forces owing to higher modes was not properly considered. Finally, a design method to account for higher mode effects within the PBPD framework was presented. The method was validated using the results from nonlinear analyses. Copyright © 2016 John Wiley & Sons, Ltd.     

广州歌剧院空间异型大跨度钢结构设计

广州歌剧院建筑造型奇特,其屋盖与幕墙组成的外围护体系为空间不规则折面组合型体,结构采用了空间折板式三向斜交单层网格结构。本文对其结构体系、构型和网格划分原则、杆件截面选取及节点形式等设计情况进行介绍,列举结构在重力荷载、风荷载、地震作用及温度作用下的变形和内力情况,对结构整体稳定分析、节点分析和铸钢节点足尺试验等关键问题进行论述,并对结构的工作机理和受力特性进行总结。结果表明,该体系对奇异建筑型体的适用性强,侧向刚度和抗震性能良好,结构工作机理以刚架作用为主,整体稳定问题不突出,结构对初始缺陷不敏感。     

Drift optimization of high‐rise buildings in earthquake zones

This paper presents a Drift Design Structural Model (DDSM) for the design optimization of high‐rise buildings in seismic zones. The model is formulated as a Generalized Single Degree of Freedom System subjected to equivalent static seismic loadings. The model objectives are: (a) the minimization of the structure weight; (b) the minimization of the structure top drift; and (c) the uniform distribution of the inter‐story drifts over the building height in order to minimize earthquake damage through the increase in plastic ductility. Seven high‐rise buildings were analysed in order to validate the model, to illustrate its use and to demonstrate its capabilities in structural design optimization in earthquake zones. The results obtained show that the DDSM performed well and consequently can be of practical value to structural designers. Copyright © 2009 John Wiley & Sons, Ltd.     

云南师范大学体育馆屋盖结构设计

云南师范大学体育馆钢屋盖采用一种新型的折板网壳结构,从形式上看类似折板结构,由96片斜置的平面桁架(两两之间共用弦杆)按相同的角度放射状布置;从受力上看属于受压壳,平面桁架的上下弦杆均受压,压力由柱顶环梁的拉力来平衡.文章结合具体的结构设计,详细介绍了钢屋盖的结构体系;分析了结构的静力性能、动力特性以及温度对结构的影响.几何非线性整体稳定分析中考虑了初始缺陷的影响,计算结果表明结构不会发生整体失稳和局部失稳.最后,介绍了结构重要部位的节点设计.     

Zur Momentenumlagerung in Elementdecken mit Gitterträgern

Moment Redistribution in Precast Plates with Lattice Girders Semi precast slabs consist of precast plates with lattice girders and an in‐situ concrete topping. The structural behaviour is nearly equivalent to monolithic slabs. However, the shear capacity at the interface between precast element and concrete topping has to design thoroughly. Although technical approvals of lattice girders do not allow non‐linear analysis due to insufficient experience, a linear elastic analysis with limited moment redistribution is permitted. For a moment redistribution of 30% the use of class B (high ductility) reinforcement is required according to DIN 1045‐1. Hereby, a sufficient rotation capacity has to be ensured for both bending reinforcement and lattice girder, too. Beam tests with lattice girders of class A (normal ductility) reinforcing steel have performed at the institute of structural concrete at RWTH Aachen University revealed high plastic rotations without reducing the shear capacity.     

Finite element prediction on the structural performance of profiled steel sheet dry board structural composite system proposed as a disaster relief shelter

Folded plate structures constructed from profiled steel sheeting connected to dry boards by self drilling, self tapping screws (known as profiled steel sheeting dry board (PSSDB) system) are being proposed as an alternative to traditional forms of roof construction. The proposed load bearing composite structural system consists of an assembly of individual PSSDB panels connected by steel angle plates at the ridges, formed to the required shape, width and span. This kind of structure has a significant advantage of removing the internal trussing and support that is normally required in a traditional trussed roof system, thus adding to livable space in a building. The introduction of this innovative system would eliminate the difficulty in constructing folded plate roof that is normally very troublesome, especially when they are made out of traditional reinforced concrete system, hence would help promote the folded plate technique of construction. This paper looks into the possibility of employing the PSSDB folded plate structure to provide an efficient emergency shelter, analysing it under the effect of static wind loading using the already established and verified Finite Element technique. Such a structure is quite conceivable in the likely event of a disaster. Firstly, its basic behaviour in the elastic range is studied checking for deflection as the main controlling design factor. Secondly, the method of enhancing the structural stiffness and performance of the system is proposed. It was found that this could be easily achieved by restraining the bottom longitudinal edges on both sides of the structure. A practical solution is proposed in this paper that can be implemented in real practice. It can be concluded that the proposed structure has a great potential to be exploited for the above-intended purpose.     

基于ANSYS的某叠臂高空作业车板式转台设计

对高空作业车转台的结构设计进行讨论,主要考虑结构的利用效率、整车轻量化设计、简化工艺生产制造流程、降低整车制造成本等问题。探讨板式结构的转台在整车设计中存在的利弊,并以结构分析为手段,运用ANSYS对高空作业车的回转机构进行有限元分析,研究板式结构回转机构在结构设计中的可应用性。以某折叠臂高空作业车回转平台的设计为例,通过受力计算结果得出结论:该板式结构转台的设计能满足整车性能、安全性,以及轻量化和工艺简单化的要求,可以运用到实际的工程机械设计中。     

Comparative study of structural material quantities of high‐rise residential buildings

A major factor in the selection of the structural system for a high‐rise building is the initial construction cost of candidate structural systems. In Korea, composite steel and concrete construction, and cast‐in‐place concrete flat plate construction are the most commonly used structural systems. However, there is a lack of data related to the relative construction costs of these two structure types. This paper compares material quantities for representative building models up to 80 stories in height using both types of structural system. Based on a typical floor plan, six models are developed and the buildings are designed for gravity and lateral loading. Quantities of materials for each model are calculated and compared. The information presented can be used with appropriate cost data to compare construction costs for the two structural system types. Copyright © 2007 John Wiley & Sons, Ltd.     

Forensic studies of a large cover‐plate steel moment‐resisting connection

A large‐size, single‐sided cover plate connection composed of a built‐up BW36×670 column and a W36×359 rolled beam section was tested in a custom‐made test fixture using the SAC Phase I loading protocol. A trapezoidal plate was used as top flange reinforcement and a rectangular plate was used as bottom flange reinforcement. The test specimen failed catastrophically at a story drift angle of 1.7% and a beam plastic rotation of 0.009 radian by fracture through the beam top flange and beam web. An ABAQUS nonlinear finite element model of the connection was prepared and analyzed. The ABAQUS data indicate that the likelihood of brittle or ductile fracture at the observed crack initiation site is very low. Fractographic and microstructure studies were conducted after testing. The fractographic analysis of the failure surface showed that the fracture initiated at the toe of a fillet weld that joined the top cover plate to the beam flange. The microstructure analysis around the crack initiation site revealed laminations in the base metal at the crack initiation site. Copyright © 2002 John Wiley & Sons, Ltd.     

Heidebroek‐Bau der Technischen Universität Dresden – Ertüchtigung und Instandsetzung des vorgespannten Faltwerkdachs

Die Dachkonstruktion des als Experimentalbau errichteten Heidebroek‐Baus ist ein Faltwerk, das aus zusammengespannten Stahlbetonfertigteilsegmenten besteht. Aufgrund von Unzulänglichkeiten in der konstruktiven Durchbildung und jahrelanger, durch eine desolate Abdichtung verursachte Durchfeuchtung des Faltwerks musste von einer bereits eingetretenen Korrosion der Spannglieder ausgegangen werden, so dass die Standsicherheit des Dachs in Frage stand. Zunächst durch temporäre Gerüsttürme als Hilfsunterstützung gesichert, wurde die Dachkonstruktion schließlich ertüchtigt und instandgesetzt. Dabei erfolgten die Baumaßnahmen bei laufendem Betrieb in der von der TU Dresden genutzten Versuchshalle. Zur Sicherstellung der ausreichenden Tragfähigkeit im Fall des Versagens einzelner Spannglieder sowie zur Verhinderung eines plötzlichen Gesamtversagens des Faltwerks durch progressiven Kollaps wurden Stahllamellen auf der Dachinnenfläche aufgeklebt und an den Stirnseiten der Falten endverankert. Die Bemessung der Lamellen einschließlich ihrer Verankerung und der Nachweis der vorhandenen Dachkonstruktion erfolgten unter Berücksichtigung der gemäß den gültigen Normen anzusetzenden Einwirkungen. Dieser Beitrag geht auf die Konzeption der Tragwerksertüchtigung sowie auf die diesbezüglichen, nach vier hauptsächlichen Grenzzuständen differenzierten Standsicherheitsnachweise ein und fasst die wesentlichen Aspekte der Ausschreibung, Vergabe und Ausführung der Sanierungsarbeiten sowie der Überwachung der Ertüchtigungs‐ und Instandsetzungsmaßnahmen zusammen. Heidebroek‐Bau at the Dresden University of Technology – Improvement and repair of the prestressed folded‐plate roof. The roof construction of the Heidebroek‐Bau, erected as an experimental building, is a folded‐plate construction comprising tied precast segments of reinforced concrete. Given the inadequacies in the design and the dampness which had penetrated the structure over a period of many years as a result of the desolate condition of the seals, it was to be assumed that the prestressing members already displayed corrosion and that the structural safety of the roof was thus to be questioned. Initially secured by way of temporary staging towers as auxiliary support, the roof construction was subsequently strengthened and repaired. The building work was accomplished without interrupting the use of the research hall by the Dresden University of Technology. To ensure a sufficient load‐bearing strength should individual prestressing members fail, and to eliminate the risk of a sudden total failure with progressive collapse of the folded‐plate construction, steel lamellae were attached to the inner surface of the roof and anchored at the ends of the folds. The dimensioning of the lamellae, including their anchoring and verification of the existing roof construction, took into account all potential influences specified by the applicable technical standards. This paper discusses the concept for improvement of the supporting structure and the corresponding differentiated verification of stability on the basis of four essential critical states, and provides an overview of key aspects of the tender process, execution of the improvement work and monitoring of the implemented strengthening and repair measures.     

Seismic assessment of RC core‐wall building capable of three plastic hinges with outrigger

In a core‐wall structure with buckling restrained braces (BRB) outrigger, locations of the plastic hinges are influenced by the outrigger action. Therefore, the designer should consider the issue and use suitable details in the plastic hinge area. The essential questions that arise here are the plastic hinge location and the design moment demand used for design of this kind of structure. In this paper, responses of the core‐wall buildings with BRB outrigger designed by using the traditional response spectrum analysis procedure are assessed by implementing the nonlinear time history analysis. The result demonstrates that the plasticity can extend over anywhere within the core‐walls specially, at the base and above or below the outrigger levels. Formation of three plastic hinges in the core‐wall is recognized suitable for the system. To control the plasticity extension in the core‐wall, it is recommended that a new modal combination method be applied to calculate the moment strength of the three plastic hinges over the height. A capacity design concept is used to design other regions of the core‐wall where the plasticity does not extend to. The proposed procedure improves behavior of the system by restricting the plasticity extension to the predefined plastic hinge regions. Copyright © 2016 John Wiley & Sons, Ltd.     

Tall building with steel plate shear walls subject to load reversal

This paper presents a state‐of‐the‐art review of research on thin unstiffened steel plate shear walls including recent research advances, in addition to a case study building that used them as the primary lateral‐force‐resisting system. Thin unstiffened steel plate shear walls are becoming an attractive alternative to traditional lateral‐force‐resistance systems because they exhibit desirable structural properties. A properly designed steel plate shear wall will have considerable energy dissipation capacity, ductility, initial stiffness and ultimate strength. Furthermore, the said walls are efficient in terms of cost and space due to their light weight, ease of construction and small footprint. The case study building is a 55‐story high‐rise system that took advantage of these properties. Details are presented regarding the design process and tools that were used to ensure a safe and efficient structure. Copyright © 2011 John Wiley & Sons, Ltd.     

Seismic performance of cover‐plate strengthened frames

This paper summarizes results and conclusions of a case study of cover‐plate strengthened frames with two, five and ten stories. The study begins with the comparison of a test results from a cover‐plate connection assembly specimen with results using a detailed nonlinear finite element analysis (FEA) model. With a strong correlation to the test specimen, more FEA models are generated and analysed in order to (a) examine the local behavior of cover‐plate profiles; various and (b) compare their performance to the simplified structural models that will be used in the static and time history analysis of those of the frames. With the reliable simple structural model of the cover‐plate connection assemblies capturing both elastic and inelastic behavior, such a model is incorporated into frames to perform nonlinear static and time history analyses. Nine frames (two‐, five‐ and ten‐story steel moment frames with and without a cover plate) are the designed for the study. For comparative purposes, the 1940 Imperial Valley (El Centro station, 0·32g PGA) and the 1994 Northridge (Newhall station, 0·59g PGA) ground motions factored to 0·3 and 0·6g are used in time‐history analyses. Global and local performance of frames are discussed in terms of plastic deformation distribution, story shear force and inelastic drift ratio. Copyright © 1999 John Wiley & Sons, Ltd.     

Reduction of inelastic seismic demands in a mid‐rise rocking wall structure designed using the displacement‐based design procedure

Precast post‐tensioned rocking wall structural system has been developed in the recent past as a damage‐avoidance structural system for seismic regions. For a widespread use of this structural system, suitable design procedures are required to ensure a reliable and well‐predicted performance under different levels of seismic hazard. In the current study, a mid‐rise 20‐story rocking wall structure is selected and designed using the displacement‐based design procedure. Furthermore, two different capacity design procedures are used to predict the increased force demands due to higher mode effects. The time history results against moderate and severe level of seismic hazards show the effectiveness of displacement‐based design procedure in predicting and controlling the displacement and drift demands, while the simplified procedure and the modified modal superposition procedure for the capacity design are found to be unconservative and conservative, respectively. To further investigate the seismic demands, modal decomposition of inelastic seismic responses is carried out, and the contribution of different modes in the total responses is calculated. Based on this improved understanding, a mitigation technique of dual gap opening is employed. A detailed discussion about the location and design strength of the extra gap‐opening is carried out by considering different performance parameters. Copyright © 2016 John Wiley & Sons, Ltd.     

折板形网壳结构的设计及研究

以某体育馆钢屋盖结构为实例 ,论述了折板网壳结构的选型、受力特点、水平推力的处理方法和模态分析。研究发现 ,该结构的自振频率呈密集型分布 ,结构的基本振动为水平振动 ,而不象平板网架那样以竖向振动为主 ,结构表现出良好的受力性能和抗震性能