• Steel and Composite Structures
• /
• 제33권1호
• /
• pp.1-18
• /
• 2019

In the present study, the behavior of steel plate shear walls (SPSW) with variable column flexural stiffness is experimentally and numerically investigated. Altogether six one-bay one-story specimens, three moment resisting frames (MRFs) and three SPSWs, were designed, fabricated and tested. Column flexural stiffness of the first specimen pair (one MRF and one SPSW) corresponded to the value required by the design codes, while for the second and third pair it was reduced by 18% and 36%, respectively. The quasi-static cyclic test result indicate that SPSW with reduced column flexural stiffness have satisfactory performance up to 4% story drift ratio, allow development of the tension field over the entire infill panel, and cause negligible column "pull-in" deformation which indicates that prescribed minimal column flexural stiffness value, according to AISC 341-10, might be conservative. In addition, finite element (FE) pushover simulations using shell elements were developed. Such FE models can predict SPSW cyclic behavior reasonably well and can be used to conduct numerical parametric analyses. It should be mentioned that these FE models were not able to reproduce column "pull-in" deformation indicating the need for further development of FE simulations with cyclic load introduction which will be part of another paper.

• Steel and Composite Structures
• /
• 제11권3호
• /
• pp.251-271
• /
• 2011

To make direct comparisons regarding the cyclic behavior of thin steel plate shear walls (TSPSWs) with different infill-to-boundary frame connections, two TSPSWs were tested under quasi-static conditions, one having the infill plate attached to the boundary frame members on all edges and the other having the infill plate connected only to the beams. Also, the bare frame that was used in the TSPSW specimens was tested to provide data for the calibration of numerical models. The connection of infill plates to surrounding frames was achieved through the use of self-drilling screws to fish plates that were welded to the frame members. The behavior of TSPSW specimens are compared and discussed with emphasis on the characteristics important in seismic response, including the initial stiffness, ultimate strength and deformation modes observed during the tests. It is shown that TSPSW specimens achieve significant ductility and energy dissipation while the ultimate failure mode resulted from infill plate fracture at the net section of the infill plate-to-boundary frame connection after substantial infill plate yielding. Experimental results are compared to monotonic pushover predictions from computer analysis using strip models and the models are found to be capable of approximating the monotonic behavior of the TSPSW specimens.

• 한국강구조학회 논문집
• /
• 제24권3호
• /
• pp.245-256
• /
• 2012

본 연구는 SC 벽체의 구조적 성능에 개구부가 주는 영향을 평가하는 목적으로 하였다. SC구조의 실험체는 개구부가 있는 실험체와 없는 실험체로 구분하였으며 개구부형상은 정사각형으로 개구부 주변의 보강과 비보강 그리고 슬리브두께를 변수로 계획하였다. 실험체의 공통된 파괴양상은 강판의 좌굴이 스터드와 스터드 사이에서 발생한 후 콘크리트의 균열이 진행되는 형태이며 개구부의 파괴형태는 수직 슬리브 벽이 개구부 안쪽으로 좌굴되는 파괴형태를 보여주었다. 또한 개구부의 슬리브 유무에 따라 강판좌굴 하중은 비슷하지만 최대압축강도는 슬리브가 있는 것이 크게 나타났다.

• 한국강구조학회 논문집
• /
• 제20권4호
• /
• pp.505-517
• /
• 2008

휨지배 거동을 나타내는 세장한 이중강판합성벽의 비탄성 거동을 예측하기 위하여 비선형 수치해석 모델이 연구되었다. 수치해석의 편리를 위하여, 제안된 모델은 비교적 단순한 모델을 가지고 비탄성 거동을 근사적으로 예측할 수 있는 거시적 모델로 개발되었다. 휨지배 거동을 나타내는 벽체에 대해서는 다중평행요소 모델이 사용되었으며, 깊은 연결보의 전단거동을 위하여 X형 대각요소 모델이 사용되었다. 각 요소의 주기거동을 예측하기 위하여 콘크리트 및 강판 요소에 대한 간략화된 일축의 주기모델을 제안하였다. 제안된 해석모델은 1자형 및 T형 단일벽과 병렬벽에 적용하였으며, 그 결과는 기존의 실험결과와 비교되었다.

• Earthquakes and Structures
• /
• 제7권5호
• /
• pp.627-645
• /
• 2014

Using OpenSees as a framework, constitutive models of reinforced, prestressed and prestressed steel fiber concrete found by the panel tests have been implemented into a finite element program called Simulation of Concrete Structures (SCS) to predict the seismic behavior of shear-critical reinforced and prestressed concrete structures. The developed finite element program was validated by tests on prestressed steel fiber concrete beams under monotonic loading, post tensioned precast concrete column under reversed cyclic loading, framed shear walls under reversed cyclic loading or shaking table excitations, and a seven-story wall building under shake table excitations. The comparison of analytical results with test outcomes indicates good agreement.

• 콘크리트학회논문집
• /
• 제19권6호
• /
• pp.685-692
• /
• 2007

낮은 전단벽과 같이 전단력에 의하여 지배 받는 철근콘크리트 부재의 경우, 전단력은 부재의 응력-변형률 이력곡선에서 핀칭 효과에 영향을 미친다. 그러나 최근의 연구에 따르면 철근의 배근 방향이 주응력 방향과 일치할 경우 철근콘크리트 부재의 응력-변형률 이력곡선에서 핀칭 효과가 없어지는 것으로 나타났다. 본 연구에서는 철근콘크리트 부재의 응력-변형률 이력곡선에서 핀칭 효과의 발생 유무를 변형률의 적합 조건을 고려한 트러스 모델을 이용하여 이론적으로 설명하였다. 해석 결과는 철근콘크리트 부재의 핀칭 효과가 철근의 배근 방향에 큰 영향을 받는 것을 보여준다. 또한 에너지소산 성능은 외력의 주응력 방향과 철근의 배근 방향 사이의 각도 차이에 따라 선형적으로 증가하지 않았다.

• 대한토목학회논문집
• /
• 제33권6호
• /
• pp.2181-2193
• /
• 2013

지금까지 수행된 개구부가 존재하는 벽체에 대한 연구는 대부분 RC 벽체에 대해서 수행되었으며, SC(Steel plate Concrete) 벽체에 설치되는 개구부에 대한 연구는 수행된 예가 적다. 최근에 국내에서 개발된 SC 벽체는 원전구조물에 일부 적용되고 있지만, 관련 설계기준인 KEPIC-SNG에서도 개구부를 갖는 SC 벽체에 대한 설계법은 명확하게 정의되지 않았다. 본 연구에서는 원전구조물내 벽체에 설치되는 SC 벽체를 대상으로 개구 저감률이 구조내력에 미치는 영향을 평가하였다. 개구 저감률을 고려한 구조내력 평가 결과는 실험 및 수치해석 결과와 비교분석하였다.

• 한국지진공학회논문집
• /
• 제23권5호
• /
• pp.239-248
• /
• 2019

In this study, the out-of-plane seismic resistance of lightly-reinforced existing walls strengthened with thick RC jacket was investigated. The thick RC jacket with a thickness of 500 mm was placed at one side of the thin existing wall with a thickness of 150 mm. At the interface between the wall and RC jacket, a tee-shaped steel section with a number of anchor bolts and dowel bars was used as the shear connector. To investigate the connection performance and strengthening effects, the cyclic loading tests of four jacketed wall specimens were performed. The tests showed that the flexural strength of the jacketed walls under out-of-plane loading was significantly increased. During the initial behavior, the tee shear connector transferred forces successfully at the interface without slip. However, as the cracking, spalling, and crushing of the concrete increased in the exiting walls, the connection performance at the interface was significantly degraded and, consequently, the strength of the jacketed walls was significantly decreased. The flexural strength of the jacketed walls with tee shear connector was estimated considering the full and partial composite actions of the tee shear connector.

• 복합신소재구조학회 논문집
• /
• 제6권2호
• /
• pp.105-117
• /
• 2015

The purpose of this study is to develop a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were experimentally performed on one unreinforced beam-column specimen and two reinforced specimens with L-type precast wall panels. The results were analyzed to find that the specimen with anchored connection experienced shear failure, while the other specimen with steel plate connection principally manifested flexural failure. The ultimate strength of the specimens was determined to be the weaker of the shear strength of top connection and flexural strength at the critical section of precast panel. In this setup of L-type panel specimens, if a push loading is applied to the reinforced concrete column on one side and push the precast concrete panel, a pull loading from upper shear connection is to be applied to the other side of the top shear connection of precast panel. Since the composite flexural behavior of the two members govern the total behavior during the push loading process, the ultimate horizontal resistance of this specimen was not directly influenced by shear strength at the top connection of precast panel. However, the RC column and PC wall panel member mainly exhibited non-composite behavior during the pull loading process. The ultimate horizontal resistance was directly influenced by the shear strength of top connection because the pull loading from the beam applied directly to the upper shear connection. The analytical result for the internal shear resistance at the connection pursuant to the anchor shear design of ACI 318M-11 Appendix-D except for the equation to predict the concrete breakout failure strength at the concrete side, principally agreed with the experimental result based on the elastic analysis of Midas-Zen by using the largest loading from experiment.

• Computers and Concrete
• /
• 제1권1호
• /
• pp.77-98
• /
• 2004

This paper presents a numerical model for simulating the nonlinear response of reinforced concrete (RC) shear walls subject to cyclic loadings. The material behavior of cracked concrete is described by an orthotropic constitutive relation with tension-stiffening and compression softening effects defining equivalent uniaxial stress-strain relation in the axes of orthotropy. Especially in making analytical predictions for inelastic behaviors of RC walls under reversed cyclic loading, some influencing factors inducing the material nonlinearities have been considered. A simple hysteretic stress-strain relation of concrete, which crosses the tension-compression region, is defined. Modification of the hysteretic stress-strain relation of steel is also introduced to reflect a pinching effect depending on the shear span ratio and to represent an average stress distribution in a cracked RC element, respectively. To assess the applicability of the constitutive model for RC element, analytical results are compared with idealized shear panel and shear wall test results under monotonic and cyclic shear loadings.