• Title/Summary/Keyword: history force

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Seismic vulnerability evaluation of a 32-story reinforced concrete building

  • Memari, A.M.;Motlagh, A.R. Yazdani;Akhtari, M.;Scanlon, A.;Ashtiany, M. Ghafory
    • Structural Engineering and Mechanics
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    • v.7 no.1
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    • pp.1-18
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    • 1999
  • Seismic evaluation of a 32-story reinforced concrete framed tube building is performed by checking damageability, safety, and toughness limit states. The evaluation is based on Standard 2800 (Iranian seismic code) which recommends equivalent lateral static force, modal superposition, or time history dynamic analysis methods to be applied. A three dimensional linearly elastic model checked by ambient vibration test results is used for the evaluation. Accelerograms of three earthquakes as well as linearly elastic design response spectra are used for dynamic analysis. Damageability is checked by considering story drift ratios. Safety is evaluated by comparing demands and capacities at the story and element force levels. Finally, toughness is studied in terms of curvature ductility of members. The paper explains the methodology selected and various aspects in detail.

A Study on Dynaniic Analysis for Earthquake Design of cable-stayed Bridges (사장교의 내진설계를 위한 동적해석에 관한 연구)

  • 이진휴;이재영;이장춘
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.1
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    • pp.103-115
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    • 1994
  • The dynamic earthquake analysis of plane cable-stayed bridge structures was formulated and implemented into a computer program which analyzes plane cable-stayed bridge structu- res subjected to initial cable tensions, member dead and live loads and seismic loads. Cable-stayed bridges were modelled as multi-degrees of freedom systems with lumped- mass. Various earthquake responses such as dynamic deflection, bending moment, shear force and cable tension were investigated by the dynamic analyses in the form of the time history analysis. The time history analysis was based on the mode superposition method. The study revealed that Fan-l type cable-syayed bridges is generally superior to other types for the earthquake proof even though aspects of deflection and section force of each type presents respective advantages and disadvantages. The study provided a method to design the sections of cable-stayed bridges under seismic loads with various design parameters related to structural types. The study is expected to be useful for effective design of cable-stayed bridges with conside- ration of earthquake.

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A Study of Housing Production by the Native Civilian Capital in the Modernizing Ages of Korea - in the Focus of Korean Style Housing Constructions in the Japan Imperialism Ages - (근대 한국의 토착민간자본(土着民間資本)에 의한 주거건축(住居建築)에 관한 연구 - 일제하(日帝下) 개량한옥건설업(改良韓屋建設業)을 중심으로-)

  • Kim, Ran-Ky
    • Journal of architectural history
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    • v.1 no.1 s.1
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    • pp.106-116
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    • 1992
  • This Study is, under the Situation that the Germ of the Autogenetic Capitalism were Broken by the Imported Force, and were Transplanted the Western Capitalism by force, and go through Imperialized Procedure, the Resaerch how the Modernizing of our Capitalistic Constructions were settled down, how Developed the Tradition of Native Architectural Technologies by those technocrafts, and What Came out the Architectural Productive Character in those Housings. The Conclusions of this Study are as Follows. First, Improvemental Tradition Housing Constructions by the Native Capital were Hard Tasks, under the Situation that Japanese Imperial Constructions have Monopolized the Whole Korean Constructions and it has been Prosperous. Second, Improvemental Tradition Housing Constructions by the Native Capital Imported Modernized Capital Management System, It, after that, Influenced our Constructions Seriously. Third, It is a Desiable Fact that Acceded Traditional Style, Provided the Small-middle Class Housing for the Common People on those Demand. Fourth, It is a Point that Contribute the Mooing Problem of Korea. Fifth, It is that Supply the Low-class Housing.

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Estimation of damage for composite laminates using sound pressure (음압을 이용한 복합 적층판의 손상평가)

  • Kim, Sung-Joon;Lee, Sang-Wook;Chae, Dong-Chul;Kim, Sung-Chan
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.503-507
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    • 2004
  • The radiated sound pressure induced by low-velocity impact is obtained by solving the Rayleigh integral equation. This paper established the sound analysis procedure using impact analysis model. For structurally radiated noise, the sound field is directly coupled to the structural motion. Therefore the impact response should be analyzed. The impact response is computed using the spring-mass model. And the influence of damage on the sound pressure and impacted force history of laminated were investigated. The results show that both radiated sound pressure and impact force history are strongly influenced by damage on laminated.

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2D numerical modeling of icebreaker advancing in ice-covered water

  • Sawamura, Junji
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.3
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    • pp.385-392
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    • 2018
  • This paper presents 2D numerical modeling to calculate ship-ice interactions that occur when an icebreaker advances into ice-covered water. The numerical model calculates repeated icebreaking of an ice plate and removal of small ice floes. The icebreaking of the ice plate is calculated using a ship-ice contact detection technique and fluid-structural interaction of ice plate bending behavior. The ship-ice interactions in small ice floes are calculated using a physically based modeling with 3DOF rigid body equations. The ice plate is broken in crushing, bending, and splitting mode. The ice floes drift by wind or current and by the force induced by the ship-ice interaction. The time history of ice force and ice floe distribution when an icebreaker advances into the ice-covered water are obtained numerically. Numerical results demonstrate that the time history of ice force and distribution of ice floes (ice channel width) depend on the ice floe size, ship motion and ice drifting by wind or current. It is shown that the numerical model of ship maneuvering in realistic ice conditions is necessary to obtain precise information about the ship in ice-covered water. The proposed numerical model can be useful to provide data of a ship operating in ice-covered water.

Effect of lateral structural systems of adjacent buildings on pounding force

  • Kheyroddin, Ali;Kioumarsi, Mahdi;Kioumarsi, Benyamin;Faraei, Aria
    • Earthquakes and Structures
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    • v.14 no.3
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    • pp.229-239
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    • 2018
  • Under strong ground motion, pounding can be caused because of the different dynamic properties between two adjacent buildings. Using different structural systems in two adjacent structures makes a difference in the lateral stiffness and thus changes the pounding force between them. In this paper, the effect of the structural system of adjacent buildings on the amount of force applied by pounding effects has been investigated. Moment resisting frame systems (MRFs), lateral X-bracing system (LBS), shear wall system (SWS) and dual system (DS) have been investigated. Four different cases has been modelled using finite element (FE) method. The number of stories of the two adjacent buildings is different in each case: case 1 with 6 and 4 stories, case 2 with 9 and 6 stories, case 3 with 15 and 6 stories and case 4 with 10 and 10 stories. The structures have been modelled three-dimensionally. Non-linear time history analysis has been done on the structures using the finite element software SAP2000. In order to model pounding effects, the non-linear gap elements have been used.

An Experimental Study on Low-Velocity Impact Test and Response of Composite Laminates (복합적층판의 저속충격시험 및 거동에 대한 실험적 연구)

  • 최익현;홍창선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.2
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    • pp.359-371
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    • 1994
  • A drop weight type impact test system is designed and set up to experimentally investigate impact responses of composite laminates subjected to the low-velocity impact. Using the test system, the impact velocity and the rebound velocity of the impactor as well as the impact force history are measured. An error of the measured data due to a difference in measuring position of the sensor is corrected and, for the estimation of real contact force history, a method of correcting an error due to friction forces is developed. Experimental methods to fix the boundary edgy of laminate specimens in impact testing are investigated and the impact tests on the specimens fixed by those methods are performed. Impact force histories and dynamic strains measured from the tests are compared with numerical results from the finite element analysis using the contact law. Consequently, the nonlinear numerical results considering the large deflection effects are agreed with the experimental results better than the linear ones.

Soil-structure interaction and axial force effect in structural vibration

  • Gao, H.;Kwok, K.C.S.;Samali, B.
    • Structural Engineering and Mechanics
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    • v.5 no.1
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    • pp.1-19
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    • 1997
  • A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

Development of a double-sliding friction damper (DSFD)

  • Shen, Shaodong;Pan, Peng;Sun, Jiangbo;Gong, Runhua;Wang, Haishen;Li, Wei
    • Smart Structures and Systems
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    • v.20 no.2
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    • pp.151-162
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    • 2017
  • In practical engineering, the friction damper is a widely used energy dissipation device because of its large deformation capacity, stable energy dissipation capability, and cost effectiveness. While based on conventional friction dampers, the double-sliding friction damper (DSFD) being proposed is different in that it features two sliding friction forces, i.e., small and large sliding friction forces, rather than a single-sliding friction force of ordinary friction dampers. The DSFD starts to deform when the force sustained exceeds the small-sliding friction force, and stops deforming when the deformation reaches a certain value. If the force sustained exceeds the large sliding friction force, it continues to deform. Such a double-sliding behavior is expected to endow structures equipped with the DSFD better performance in both small and large earthquakes. The configuration and working mechanism of the DSFD is described and analyzed. Quasi-static loading tests and finite element analyses were conducted to investigate its hysteretic behavior. Finally, time history analysis of the single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) systems were performed to investigate the seismic performance of DSFD-equipped structures. For the purpose of comparison, tests on systems equipped with conventional friction dampers were also performed. The proposed DSFD can be realized perfectly, and the DSFD-equipped structures provide better performances than those equipped with conventional friction dampers in terms of interstory drift and floor acceleration. In particular, for the MDOF system, the DSFD helps the structural system to have a uniform distributed interstory drift.

Structural Analysis using Equivalent Models of Active Control Devices (능동형 제진장치의 등가모델을 이용한 구조해석)

  • Park, Ji-Hun;Yun, Soo-Yong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.4
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    • pp.339-346
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    • 2012
  • In this paper, equivalent models for active control devices are proposed so that building structures with such devices are analyzed using commercial structural analysis programs for the assessment of the structural members under active vibration control. Equivalent link models represent active control device with a virtual linear spring and dashpot, and equivalent force models are control force history acting at the installation point in structural models. Active controllers are designed based on the reduced-order models for a vertical cantilever model and a high-rise building model and corresponding equivalent models are determined from control gain matrices. Based on acceleration, displacement and member force responses, the effectiveness of the equivalent models is verified. As a result, proposed equivalent models, of which equivalent link model showed better performance, appear to enable detailed investigation of structural behavior to the extent of member force level.