• Title/Summary/Keyword: Large-span structure

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Mechanical Behavior of Cable Net Structures Considering Sag Ratio (새그 비를 고려한 케이블 네트 구조물의 역학적 거동)

  • Park, Kang-Geun;Lee, Dong-Woo
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.3
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    • pp.47-58
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    • 2016
  • Cable network system is a flexible lightweight structure which curved cables can transmit only tensile forces. The weight of cable roof dramatically can reduce when the length becomes large. The cable network system is too flexible, most cable systems are stabilized by pretension forces. The tensile force of cable system is greatly influenced by the sag ratio and pretension forces. Determining initial sag ratio of cable roof system is essential in a design process of cable structures. Final sag ratio and pretension depends on initial installed sag and on proper handling during installation. The design shape of cable system has an affect on the sag and pretension, and must be determined using well-defined design philosophy. This paper is carried out the comparative data of the deflection and tensile forces on the geometric non-linear analysis of cable network systems according to sag ratio. The study of cable network system is provided to technical informations for the design of a large span cable roof, analytical results are compared with the results of other researchers. Structural nonlinear analysis of systems having cable elements is relatively complex than other rigid structural systems because displacements are large as a reason of flexibility, initial prestress is applied to cables in order to increase the rigidity, and then divergence of nonlinear analysis occurs rather frequently. Therefore, cable network systems do not exhibit a typical nonlinear behavior, iterative method that can handle geometric nonlinearities are necessary.

A Study on the Application of Gypsum Board through the Application of Fire Resistance Ceiling Structure (내화천장구조 적용을 통한 석고보드 활용 확대에 관한 연구)

  • Choi, Dong-ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.217-218
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    • 2019
  • Fire resistance ceiling system is the structure of which the ceiling installed under the slave of the structure has the fire resistance performance. Because of having the fire resistance performance, fire resistive coatings on steel beams can be reduced and large span structures can be constructed. So, it have advantages of convenience for construction, shorten for construction time and cost reducing. In foreign country, it is general that one system consisting of slave and ceiling is constructed as a fire resistance system, in these cases, gypsum boards are mostly used as ceiling materials. The purpose of this study was to explain the possibility of expanding the use of gypsum boards by securing fire resistance performance of these ceilings.

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Spatial mechanical behaviors of long-span V-shape rigid frame composite arch bridges

  • Gou, Hongye;Pu, Qianhui;Wang, Junming;Chen, Zeyu;Qin, Shiqiang
    • Structural Engineering and Mechanics
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    • v.47 no.1
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    • pp.59-73
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    • 2013
  • The Xiaolan channel super large bridge is unique in style and with greatest span in the world with a total length of 7686.57 m. The main bridge with spans arranged as 100m+220m+100m is a combined structure composed of prestressed concrete V-shape rigid frame and concrete-filled steel tubular flexible arch. First of all, the author compiles APDL command flow program by using the unit birth-death technique and establishes simulation calculation model in the whole construction process. The creep characteristics of concrete are also taken into account. The force ratio of the suspender, arch and beam is discussed. The authors conduct studies on the three-plate webs's rule of shear stress distribution, the box girder's longitudinal bending normal stress on every construction stage, meanwhile the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge's box girder. Results show that, as a new combined bridge, it is featured by: Girder and arch resist forces together; Moment effects of the structure are mainly presented as compressed arch and tensioned girder; The bridge type brings the girder and arch on resisting forces into full play; Great in vertical stiffness and slender in appearance.

Seismic Response Analysis of Dome-Shaped Large Spatial Structures According to TMD Installation (TMD 설치에 따른 돔 형상 대공간 구조물의 지진응답분석)

  • Ku, Seung-Yeon;Yoo, Sang-Ho;Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.27-34
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    • 2023
  • In this study, the seismic response characteristics of the three analysis model with or without TMD were investigated to find out the effective dome shape. The three analysis models are rib type, lattice type and geodesic type dome structure composed of space frame. The maximum vertical and horizontal displacements were evaluated at 1/4 point of the span by applying the resonance harmonic load and historical earthquake loads (El Centro, Kobe, Northridge earthquakes). The study of the effective TMD installation position for the dome structure shows that seismic response control was effective when eight TMDs were installed in all types of analysis model. The investigation of the efficiency of TMD according to dome shape presents that lattice dome and geodesic dome show excellent control performance, while rib dome shows different control performance depending on the historical seismic loads. Therefore, lattice and geodesic types are desirable for seismic response reduction using TMD compared to rib type.

Mechanical Properties of Composite Materials Composed of Structural Steel and Structural Glued Laminated Timber (구조용 강철과 구조용 집성재 복합재료 보의 역학적 성질)

  • Jang, Sangsik;Kim, Yunhui;Jang, Youngik
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.4
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    • pp.300-309
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    • 2009
  • The effective utilization of wood structure is encouraged to preserve natural resources and the global environment. Long-span and large-scale structures are preferred to promote demand for wood. This study attempts to develop new Fire-resistance Composite Material composed of Structural steel and Structural glued laminated timber for long-span and large-scale structures. Prior to take a fire-resistance test, compare properties of bending strength with Composite material composed of Structural steel and Structural glued laminated timber, structural steel and structural provides the stability of the structure, but the structural glued laminated timber has high value elasticity of bending. Using the Composite material will improve structural stability and Eco-friend construction environment.

A Study on the Equivalent Static Wind Load Estimation of Large Span Roofs (대스팬 지붕구조물의 등가정적 풍하중 산정에 관한 연구)

  • Lee, Myung-Ho;Kim, Ji-Young;Kim, Dae-Young;Kim, Sang-Dae
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.1 s.19
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    • pp.83-90
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    • 2006
  • The GF(Gust Factor) method is usually used as a method to evaluate equivalent static wind loads for general structures. The GF method is performed on the assumption that the shape of the equivalent static wind load profile is typically similar to that of mean wind loads. The shape of fluctuating wind loads could be quite different with that of the mean wind loads in case of large-span structures. So, the effect of higher modes as well as first mode must be considered to evaluate the wind loads. In this study, the ACS (Advanced Conditional Sampling) method is suggested to evaluate of equivalent static wind loads after investigating about GF and LRC method. The An method ran derive effective static wind loads by combining wind pressures and inertia forces of a structure chosen at a maximum load effect. The maximum load effect is assessed with the time history analysis using pressure data measured in wind tunnel tests. Equivalent static wind loads evaluated using ACS, GF, and LRC methods are compared to verify the effectiveness of ACS method.

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Wireless operational modal analysis of a multi-span prestressed concrete bridge for structural identification

  • Whelan, Matthew J.;Gangone, Michael V.;Janoyan, Kerop D.;Hoult, Neil A.;Middleton, Campbell R.;Soga, Kenichi
    • Smart Structures and Systems
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    • v.6 no.5_6
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    • pp.579-593
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    • 2010
  • Low-power radio frequency (RF) chip transceiver technology and the associated structural health monitoring platforms have matured recently to enable high-rate, lossless transmission of measurement data across large-scale sensor networks. The intrinsic value of these advanced capabilities is the allowance for high-quality, rapid operational modal analysis of in-service structures using distributed accelerometers to experimentally characterize the dynamic response. From the analysis afforded through these dynamic data sets, structural identification techniques can then be utilized to develop a well calibrated finite element (FE) model of the structure for baseline development, extended analytical structural evaluation, and load response assessment. This paper presents a case study in which operational modal analysis is performed on a three-span prestressed reinforced concrete bridge using a wireless sensor network. The low-power wireless platform deployed supported a high-rate, lossless transmission protocol enabling real-time remote acquisition of the vibration response as recorded by twenty-nine accelerometers at a 256 Sps sampling rate. Several instrumentation layouts were utilized to assess the global multi-span response using a stationary sensor array as well as the spatially refined response of a single span using roving sensors and reference-based techniques. Subsequent structural identification using FE modeling and iterative updating through comparison with the experimental analysis is then documented to demonstrate the inherent value in dynamic response measurement across structural systems using high-rate wireless sensor networks.

A Comparative Study on the Buckling Characteristics of Single-layer and Double-layer Spherical Space Frame Structure with Triangular Network Pattern (삼각형 네트워크를 갖는 단층 및 복층 구형 스페이스 프레임 구조물의 좌굴특성에 관한 비교 연구)

  • 이호상;정환목;권영환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.251-257
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    • 1998
  • Spherical space frame structure with triangular network pattern, which has the various characteristics for the mechanic property, a funtional property, an aesthetic property and so on, has often been used as one of the most efficient space structures. It is expected that this type will be used widely in large-span structural roofs. But because this structure is made of network by combination of line elements there me many nodes therefore, the structure behavior is very complicated and there can be an overall collapse of structure by buckling phenomenon if the external force reaches a limitation. This kind of buckling is due to geometric shape, network pattern, the number of layer and so on, of structure. Therefore spherical space frame with triangle network pattern have attracted many designers and researchers attention all over the world. The number of layer of space frame is divided in to the simgle, double, multi layer. That is important element which is considered deeply in the beginning of structural design. The buckling characteristics of single-layer model and double-layer model for the spherical space frame structure with triangular network pattern are evaluated and the buckling loads of these types are compared with investigation their structural efficiency in this study.

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Seismic response of single-arch large-span fabricated subway station structure

  • He, Huafei;Li, Zhaoping
    • Earthquakes and Structures
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    • v.23 no.1
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    • pp.101-113
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    • 2022
  • A new type of fabricated subway station construction technology can effectively solve these problems. For a new type of metro structure form, it is necessary to clarify its mechanical properties, especially the seismic performance. A soil-structure elastoplastic finite element model is established to perform three-dimensional nonlinear dynamic time-history analysis based on the first fabricated station structure-Yuanjiadian station of Changchun Metro Line 2, China. Firstly, the nonlinear seismic response characteristics of the fabricated and cast-in-place subway stations under different seismic wave excitations are compared and analyzed. Then, a comprehensive analysis of several important parameters that may affect the seismic response of fabricated subway stations is given. The results show that the maximum plastic strain, the interlayer deformation, and the internal force of fabricated station structures are smaller than that of cast-in-place structure, which indicates that the fabricated station structure has good deformation coordination capability and mechanical properties. The seismic responses of fabricated stations were mainly affected by the soil-structure stiffness ratio, the soil inertia effect, and earthquake load conditions rarely mentioned in cast-in-place stations. The critical parameters have little effect on the interlayer deformation but significantly affect the joints' opening distance and contact stress, which can be used as the evaluation index of the seismic performance of fabricated station structures. The presented results can better understand the seismic responses and guide the seismic design of the fabricated station.

A Study on Unstable Phenomenon of Space Truss Structures Considering Initial Imperfection (트러스형 공간구조물의 초기 불완전을 고려한 불안정 현상에 관한 연구)

  • Lee, Jin-Hyouk;Baik, Tai-Soon;Shon, Su-Deok;Kim, Seung-Deog;Kang, Moon-Myung
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.63-71
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    • 2004
  • The structural space is gradually wide and is wanting agreeable environment by the requirement and necessity of people who lives modem stage. The building coincides with such requirements and is the high rise building actual circumstances which is doing ultra-large. The confirmed report of the technology to organize great merit is becoming currently considerably important issue in constructing a building field. Thus, this paper examine closely for nonlinear unstable taking a picture uneasiness height of prosperity considering to initial imperfection by a numerical method with a space frame structure of discrete system in large space structure. Based on previous investigation method, this paper induce nodal stiffness matrix of solid truss elements considering geometrical nonlinear using finite element method. In this paper, three types of space structure considered; i) 1-free node space structure, ii) 2-free node space structure, iii) multi-free node space structure. It apply the above examples to a nonlinear program, next, grasp the characteristic of an unstable conduct and the result was a clearing low.

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