• 제목, 요약, 키워드: lateral stiffness

검색결과 767건 처리시간 0.04초

Experimental study on shear damage and lateral stiffness of transfer column in SRC-RC hybrid structure

  • Wu, Kai;Zhai, Jiangpeng;Xue, Jianyang;Xu, Fangyuan;Zhao, Hongtie
    • Computers and Concrete
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    • v.23 no.5
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    • pp.335-349
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    • 2019
  • A low-cycle loading experiment of 16 transfer column specimens was conducted to study the influence of parameters, likes the extension length of shape steel, the ratio of shape steel, the axial compression ratio and the volumetric ratio of stirrups, on the shear distribution between steel and concrete, the concrete damage state and the degradation of lateral stiffness. Shear force of shape steel reacted at the core area of concrete section and led to tension effect which accelerated the damage of concrete. At the same time, the damage of concrete diminished its shear capacity and resulted in the shear enlargement of shape steel. The interplay between concrete damage and shear force of shape steel ultimately made for the failures of transfer columns. With the increase of extension length, the lateral stiffness first increases and then decreases, but the stiffness degradation gets faster; With the increase of steel ratio, the lateral stiffness remains the same, but the degradation gets faster; With the increase of the axial compression ratio, the lateral stiffness increases, and the degradation is more significant. Using more stirrups can effectively restrain the development of cracks and increase the lateral stiffness at the yielding point. Also, a formula for calculating the yielding lateral stiffness is obtained by a regression analysis of the test data.

Identifying stiffness irregularity in buildings using fundamental lateral mode shape

  • Vijayanarayanan, A.R.;Goswami, Rupen;Murty, C.V.R.
    • Earthquakes and Structures
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    • v.12 no.4
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    • pp.437-448
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    • 2017
  • Soft or extreme soft storeys in multi-storied buildings cause localized damage (and even collapse) during strong earthquake shaking. The presence of such soft or extremely soft storey is identified through provisions of vertical stiffness irregularity in seismic design codes. Identification of the irregularity in a building requires estimation of lateral translational stiffness of each storey. Estimation of lateral translational stiffness can be an arduous task. A simple procedure is presented to estimate storey stiffness using only properties of fundamental lateral translational mode of oscillation (namely natural period and associated mode shape), which are readily available to designers at the end of analysis stage. In addition, simplified analytical expressions are provided towards identifying stiffness irregularity. Results of linear elastic time-history analyses indicate that the proposed procedure captures the irregularity in storey stiffness in both low- and mid-rise buildings.

철도차량용 코일스프링 횡강성 해석 (Analysis on the Lateral Stiffness of Coil Spring for Railway Vehicle)

  • 허현무;안다훈
    • 한국산학기술학회논문지
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    • v.19 no.9
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    • pp.84-90
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    • 2018
  • 철도차량의 거동을 해석하기 위하여 다물체 동역학 모델을 구성함에 있어 현가시스템을 구성하는 스프링, 댐퍼와 같은 현가요소에 대한 스프링강성이나 감쇠계수와 같은 물성치 파악은 매우 중요하다. 그 중 1차, 2차 현가시스템에 주로 활용되고 있는 코일스프링에 대한 동역학 모델을 구성함에 있어 축방향 강성은 도면이나 설계자료에 명확하게 명시되어 있지만 횡방향에 대한 물성은 명시되어 있지 않아 동역학 해석 모델 구성에 어려움을 안고 있다. 따라서 본 논문에서는 철도차량의 현가시스템에 폭 넓게 적용되고 있는 코일스프링에 대한 횡강성을 해석하기 위한 모델에 대하여 검토하고자 한다. 코일스프링 시료에 대한 횡강성을 해석하고자 유한요소해석 방법을 수행하였고 Krettek와 Sobczak의 코일스프링 횡강성 해석모델을 적용하여 수치해석을 수행하였다. 그리고 코일스프링 시료를 대상으로 횡강성 특성시험을 수행하여 해석모델과의 적합성을 검토하였다. 시험결과와 비교한 결과, Krettek와 Sobczak의 코일스프링 횡강성 해석모델을 적용하고 보정계수를 수정한 결과가 시험결과에 근사한 결과를 얻을 수 있었다.

H형 침목에 관한 연구 (A Study on the H-typed Railway Sleeper)

  • 배현웅;배상원;김해곤;이진옥;임남형
    • 한국철도학회:학술대회논문집
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    • pp.680-683
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    • 2010
  • The lateral stiffness of the track structure is very important mechanical property to prevent the track buckling and progress of misalignment. The increasing methods of the lateral stiffness of the track structure are the following; increases of the lateral ballast resistance, and increases of the lateral stiffness of the track panel. In order to increase the lateral stiffness of the tack panel, some of the sleepers resist together against the lateral movement can be the most economical and mechanical method. In this paper, H-typed sleeper developed to solve this problem is introduced and the mechanical advantages of this sleeper are investigated.

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강성골조의 수평강성을 반영한 코어 아웃리거 구조시스템의 최적위치에 대한 제안 (Proposal for Optimal Core Outrigger Position Reflecting Lateral Stiffness of Rigid Frame)

  • 김형기
    • 대한건축학회논문집
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    • v.36 no.8
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    • pp.137-144
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    • 2020
  • The aim of this study is to propose the more reasonable and more comprehensive method than existing methods to predict the optimal core outrigger position in high-rise building. To attain this goal, a 54 existing analysis data about the optimal position of core outrigger system were analyzed and studied. In this analysis data, the major parameters were the outrigger stiffness, the shear wall stiffness, the stiffness of column linked in outrigger, the stiffness of frame, lateral stiffness ratio between rigid frame and shear wall, and so on. This research made a proposal concerning the method of predicting the optimum core outrigger position reflecting the effect of frame stiffness. Also the research results presented in this paper offered the valuable data of structural design for looking for the optimal location of outrigger system in high-rise building.

횡강성 영향행렬을 이용한 고층건물의 횡변위 제어 및 단면 재산정 방안 (Lateral Drift Control and Resizing Technique for Tall Buildings using Lateral-Stiffness Influence Matrix)

  • 이한주;김치경;김호수
    • 한국전산구조공학회논문집
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    • v.15 no.2
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    • pp.271-279
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    • 2002
  • 본 연구에서는 횡강성 영향행렬을 이용한 최적설계의 효율성을 높이기 위해 각 층에서 층별 영향행렬을 구하는 계산모듈을 개발하고 가상하중법에 의한 민감도 해석을 수행한다. 아울러 최적설계결과를 실무에 직접 적용할 수 있도록 층별 횡강성 증대계수에 근거하여 횡하중 저항시스템의 부재단면크기를 재산정하는 방안을 강구한다. 이를 위해 단면 재산정 방안은 연속형과 이산형 단면설계법으로 나누어 고려되며, 단면특성과 단면치수와의 관계가 설정된다. 특히 강도구속조건에 대한 초기설계가 먼저 수행된 후 횡변위 구속조건을 초과하는 횡변위를 제어하는데 있어서 횡하중 저항 시스템만이 저항하도록 설계한다. 본 연구에서 제안된 고층건물의 횡변위 제어 및 단면 재산정 방안을 검토하기 위해 두 가지 형태의 45층 삼차원 구조물이 고려된다.

원자 현미경 탐침의 수평방향 힘 교정에 미치는 접촉 강성의 영향 (Effect of Contact Stiffness on Lateral Force Calibration of Atomic Force Microscopy Cantilever)

  • ;전기준;정구현
    • Tribology and Lubricants
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    • v.28 no.6
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    • pp.289-296
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    • 2012
  • Atomic force microscopy (AFM) has been used for imaging surfaces and measuring surface forces at the nano-scale. Force calibration is important for the quantitative measurement of forces at the nano-scale using AFM. Normal force calibration is relatively straightforward, whereas the lateral force calibration is more complicated since the lateral stiffness of the cantilever is often comparable to the contact stiffness. In this work, the lateral force calibrations of the rectangular cantilever were performed using torsional Sader's method, thermal noise method, and wedge calibration method. The lateral optical lever sensitivity for the thermal noise method was determined from the friction loop under various normal forces as well. Experimental results showed that the discrepancies among the results of the different methods were as large as 30% due to the effect of the contact stiffness on the lateral force calibration of the cantilever used in this work. After correction for the effect of contact stiffness, all the calibration results agreed with each other, within experimental uncertainties.

4개의 외측 소족지 중족 족지 관절의 탈구 후 발생한 관절의 강직에서 시행한 절제 관절 성형술(1예 보고) (Resection Arthroplasty for the Treatment of Joint Stiffness after Dislocation of the Four Lateral Lesser Metatarsophalangeal Joints (A Case Report))

  • 박철현;이우천
    • 대한족부족관절학회지
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    • v.16 no.1
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    • pp.58-61
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    • 2012
  • Motion of the metatarsophalangeal joints is essential for the normal gait. Therefore it is important to recover the motion of normal joint in the treatment of stiffness of the metatarsophalangeal joints. However, there have been no report about the treatment of stiffness of the four lateral lesser metatarsophalangeal joints yet. We report an experience that good clinical and radiographic results were obtained after resection arthroplasty for the post-traumatic stiffness of the four lateral lesser metatarsophalangeal joints.

강성제어 구조물을 이용한 수평구동형 박막 PZT 엑츄에이터의 설계, 제작 및 특성평가 (Design, Fabrication and Characterization of Lateral PZT actuator using Stiffness Control)

  • 서영호;최두선;이준형;이택민;제태진;황경현
    • 한국정밀공학회:학술대회논문집
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    • pp.756-759
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    • 2004
  • We present a piezoelectric actuator using stiffness control and stroke amplification mechanism in order to make large lateral displacement. In this work, we suggest stiffness control approach that generates lateral displacement by increasing the vertical stiffness and reducing the lateral stiffness using additional structure. In addition, an additional structure of a serpentine spring amplifies the lateral displacement like leverage structure. The suggested lateral PZT actuator (bellows actuator) consists of serpentine spring and PZT/electrode layer which is located at the edge of the serpentine spring. The edge of the serpentine spring prevents the vertical motion of PZT layer, while the other edge of the serpentine spring makes stroke amplification like leverage structure. We have determined dimensions of the bellows actuator using ANSYS simulation. Length, width and thickness of PZT layer are 135$\mu$m, 20$\mu$m and 0.4$\mu$m, respectively. Dimensions of the silicon serpentine spring are thickness of 25$\mu$m, length of 300$\mu$m, and width of 5$\mu$m. The bellows actuator has been fabricated by SOI wafer with 25$\mu$m-top silicon and 1$\mu$m-buried oxide layer. The bellows actuator shows the maximum 3.93$\pm$0.2$\mu$m lateral displacement at 16V with 1Hz sinusoidal voltage input. In the frequency response test, the fabricated bellows actuator showed consistent displacement from 1Hz to 1kHz at 10V. From experimental study, we found the bellows actuator using thin film PZT and silicon serpentine spring generated mainly laterally displacement not vertical displacement at 16V, and serpentine spring played role of stroke amplification.

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Seismic performance of lateral load resisting systems

  • Subramanian, K.;Velayutham, M.
    • Structural Engineering and Mechanics
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    • v.51 no.3
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    • pp.487-502
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    • 2014
  • In buildings structures, the flexural stiffness reduction of beams and columns due to concrete cracking plays an important role in the nonlinear load-deformation response of reinforced concrete structures under service loads. Most Seismic Design Codes do not precise effective stiffness to be used in seismic analysis for structures of reinforced concrete elements, therefore uncracked section properties are usually considered in computing structural stiffness. But, uncracked stiffness will never be fully recovered during or after seismic response. In the present study, the effect of concrete cracking on the lateral response of structure has been taken into account. Totally 120 cases of 3 Dimensional Dynamic Analysis which considers the real and accidental torsional effects are performed using ETABS to determine the effective structural system across the height, which ensures the performance and the economic dimensions that achieve the saving in concrete and steel amounts thus achieve lower cost. The result findings exhibits that the dual system was the most efficient lateral load resisting system based on deflection criterion, as they yielded the least values of lateral displacements and inter-storey drifts. The shear wall system was the most economical lateral load resisting compared to moment resisting frame and dual system but they yielded the large values of lateral displacements in top storeys. Wall systems executes tremendous stiffness at the lower levels of the building, while moment frames typically restrain considerable deformations and provide significant energy dissipation under inelastic deformations at the upper levels. Cracking found to be more impact over moment resisting frames compared to the Shear wall systems. The behavior of various lateral load resisting systems with respect to time period, mode shapes, storey drift etc. are discussed in detail.