• 제목/요약/키워드: dynamic structure

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진동대실험을 통한 축소 아치구조물의 고유진동주기 분석 (Natural Vibration Period of Small-scaled Arch Structure by Shaking Table Test)

  • 김기철;강주원
    • 한국공간구조학회논문집
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    • 제15권4호
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    • pp.107-114
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    • 2015
  • Large spatial structures can not easily predict the dynamic behavior due to the lack of construction and design practices. The spatial structures are generally analyzed through the numerical simulation and experimental test in order to investigate the seismic response of large spatial structures. In the case of analysis for seismic response of large spatial structure, the many studies by the numerical analysis was carried out, researches by the shaking table test are very rare. In this study, a shaking table test of a small-scale arch structure was conducted and the dynamic characteristics of arch structure are analyzed. And the dynamic characteristics of arch structures are investigated according to the various column cross-section and length. It is found that the natural vibration periods of the small-scaled arch structure that have large column stiffness are very similar to the natural vibration period of the non-column arch structure. And in case of arch structure with large column stiffness, primary natural frequency period by numerical analysis is very similar to the primary natural frequency period of by shaking table test. These are because the dynamic characteristics of the roof structure are affected by the column stiffness of the spatial structure.

Analysis on the dynamic characteristics of RAC frame structures

  • Wang, Changqing;Xiao, Jianzhuang
    • Structural Engineering and Mechanics
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    • 제64권4호
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    • pp.461-472
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    • 2017
  • The dynamic tests of recycled aggregate concrete (RAC) are carried out, the rate-dependent mechanical models of RAC are proposed. The dynamic mechanical behaviors of RAC frame structure are investigated by adopting the numerical simulation method of the finite element. It is indicated that the lateral stiffness and the hysteresis loops of RAC frame structure obtained from the numerical simulation agree well with the test results, more so for the numerical simulation which is considered the strain rate effect than for the numerical simulation with strain rate excluded. The natural vibration frequency and the lateral stiffness increase with the increase of the strain rate. The dynamic model of the lateral stiffness is proposed, which is reasonably applied to describe the effect of the strain rate on the lateral stiffness of RAC frame structure. The effect of the strain rate on the structural deformation and capacity of RAC is analyzed. The analyses show that the inter-story drift decreases with the increase of the strain rate. However, with the increasing strain rate, the structural capacity increases. The dynamic models of the base shear coefficient and the overturning moment of RAC frame structure are developed. The dynamic models are important and can be used to evaluate the strength deterioration of RAC structure under dynamic loading.

지반-구조물 상호작용을 고려한 장대교량의 동적 거동 (Dynamic Behavior of a Long-Span Bridge Considering Soil-Structure Interaction)

  • 임채민;박장호;신영석
    • 한국안전학회지
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    • 제19권2호
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    • pp.119-124
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    • 2004
  • The effect of soil-structure interaction becomes important in the design of civil structures such as long-span bridges, which are constructed in the site composed of soft soil. Many methodologies have been developed to account for the proper consideration of soil-structure interaction effect. However, it is difficult to estimate soil-structure interaction effect accurately becaused of many uncertainties. This paper presents the results of study on soil-structure interaction and dynamic response of a long-span bridge designed in the site composed of soft soil. The effect of the soft soil was evaluated by the use of computer program SASSI and a long-span bridge structure was modeled by finite elements. Dynamic response characteristics of a long-span bridge considering soil-structure interaction wereinvestigated.

개루프제어로 이송되는 공작기계 구조물의 동적 거동을 위한 유한 요소 해석 (Finite element analysis for dynamic behavior of a machine tool structure fed in open loop control)

  • 최진우;이태홍
    • 한국생산제조학회지
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    • 제19권5호
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    • pp.596-602
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    • 2010
  • In this study, a fmite element model was developed for analysis of feeding a structure in open loop control The finite element analysis (FEA) can simulate dynamic behavior of the structure of a machine tool rapidly traveling with a screw feeding driving system. The feeding mechanism was implemented with screw element of the FEA tool used in this study. The procedure was developed for the dynamic transient FEA. First, motion parameters such as jerk and velocity were introduced for the structure to be fed in open loop control When its traveling distance was determined, set-points for the distance were generated based on the motion parameters. The set-points were applied to the FE model constructed for the traveling structure. The FEA was executed and evaluated. In this study, the FEA procedure was applied to the column of a machine tool and the dynamic behavior of the column was evaluated. The FEA helps in evaluation of the motion characteristics of a structure. The convergence time of the structure vibration posterior to feeding termination can be estimated and the stiffness of the flexible structure is also evaluated against jerk, and acceleration. It provides the feeding force which is helpful in selection of the feeding motor.

Effect of soil pile structure interaction on dynamic characteristics of jacket type offshore platforms

  • Asgarian, Behrouz;Shokrgozar, Hamed Rahman;Shahcheraghi, Davoud;Ghasemzadeh, Hasan
    • Coupled systems mechanics
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    • 제1권4호
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    • pp.381-395
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    • 2012
  • Dynamic response of Pile Supported Structures is highly depended on Soil Pile Structure Interaction. In this paper, by comparison of experimental and numerical dynamic responses of a prototype jacket offshore platform for both hinge based and pile supported boundary conditions, effect of soil-pile-structure interaction on dynamic characteristics of this platform is studied. Jacket and deck of a prototype platform is installed on a hinge-based case first and then platform is installed on eight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of platform in term of natural frequencies, mode shapes and modal damping are compared for both cases. Effects of adding and removing vertical bracing members in top bay of jacket on dynamic characteristics of platform for both boundary conditions are also studied. Numerical simulation of responses for the studied platform is also performed for both mentioned cases using capability of ABAQUS and SACS software. The 3D model using ABAQUS software is created using solid elements for soil and beam elements for jacket, deck and pile members. Mohr-Coulomb failure criterion and pile-soil interface element are used for considering nonlinear pile soil structure interaction. Simplified modeling of soil-pile-structure interaction effect is also studied using SACS software. It is observed that dynamic characteristics of the system changes significantly due to soil-pile-structure interaction. Meanwhile, both of complex and simplified (ABAQUS and SACS, respectively) models can predict this effect accurately for such platforms subjected to dynamic loading in small range of deformation.

平坦氷荷重을 받는 細長形 해양구조물의 動的 거동 (Dynamic Responses of a Slender Offshore Structure Subject to Level Ice Load)

  • 최경식
    • 한국해양공학회지
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    • 제9권2호
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    • pp.156-166
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    • 1995
  • Regrading the development of offshore natural gas field near Sakhalin Island which is an ice-infested area, this study aims to estimate the dynamic ice load for construction of offshore structures operating in this region. In this paper the design ice load and dynamic responses of a slender Arctic structure upon continuous ice movement are sutdied. Crushing agter a certain elastic deformation is assumed as a primary failure mechanism at the contact zone between semi-infinite level ice edge and the face of structure. Dynamic interaction forces are calculated using a modified Korzhavin's equation and a two-dimensional ice-structure interaction model is adopted. To verify the numerical model, dynamic analysis is performed for on of the Baltic Sea channel markers whose response patterns were presiously observed.

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경관의 동태성에 관한 연구 (A Study on Dynamic Character of Landscape)

  • 강영조
    • 한국조경학회지
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    • 제27권3호
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    • pp.39-49
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    • 1999
  • The objective of this study is to characterize the landscape retaining dynamic character through the distinction between the spatial structure and the landscape. In this study, the landscape was characterized by the image of environment viewed by human being. Firstly, the landscape was disscussed in terms of such three element as the environment viewed by human being, the psychological detachment from the environment and the meaning of image. Secondly, the dynamic character of the landscape was determined by the comparision between the spatial structure of the static elements and the landscape experience through the case study Soshe garden. In the study found that landscape experience depend on the dynamic viewpoint and human views while the spatial structure is stable and static. This study also found that landscape is an open system which can be diachronically transformed by human value, while spatial structure is a synchronic closed system.

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일차 Dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The Design of Variable Structure Controller for the Systems Having the First Order Dynamic)

  • 박귀태;최종경;김동식
    • 대한전기학회논문지
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    • 제41권4호
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    • pp.392-399
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    • 1992
  • This paper will describe the application of variable structure control theory to the first order dynamic system and verify its robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC,DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which is regarded as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

일차 dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The design of variable structure controller for the systems having the first order dynamic)

  • 박귀태;최중경;강윤관
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.179-184
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    • 1991
  • This paper will describe the application for variable structure control theory to the first order dynamic system and verify it's robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC, DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which regards as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

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