Loading [MathJax]/jax/output/CommonHTML/jax.js
  • Title/Summary/Keyword: 연성도 평가

Search Result 875, Processing Time 0.029 seconds

Effect of ties on the ductility in reinforced concrete rectangular column (띠철근 형상이 철근 콘크리트 사각형 기둥의 연성에 미치는 영향)

  • Han, Chang-Yun;Kim, Chang-Hoon;Park, Sang-Yeol;Jwa, Yong-Hyun
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2009.05a
    • /
    • pp.81-82
    • /
    • 2009
  • The purpose of this study is to evaluate the influence that shape of tie has on the ductility of reinforce concrete rectangular column with experiment. There is the standard of the shape and arrengement of tie bar for RC column, but nevertheless currently a tie used in some fields under construction has been constructed in different way from the design for the convenience of construction. A research was required to analyze the problem on the behavior of RC column caused from a shoddy and fault construction of tie, and then evaluate the safety.

  • PDF

Evaluation on Seismic Performance of the Columns in Concrete Moment Frames (모멘트 골조 기둥의 구조 성능평가)

  • 한상환;박성일
    • Journal of the Korea Concrete Institute
    • /
    • v.14 no.4
    • /
    • pp.513-520
    • /
    • 2002
  • This study is to evaluate the structural performance of columns in concrete moment frame. For this purpose the results of previous experimental studies were collected and compared. The experimental variables considered in this study are existance of lap splice within the possible plastic hinge region during an earthquake, ratio of longitudinal reinforcement axial load and the transverse reinforcement ratio. The strength, deformation, ductility capacity and the length of plastic hinge are compared in this study.

Adhesion reliability of flexible copper clad laminate under constant temperature and humidity condition by thickness of Ni/Cr seed layer (항온항습 조건하에서 Ni/Cr 층의 두께에 따른 FCCL의 접합 신뢰성 평가)

  • Choi, Jung-Hyun;Noh, Bo-In;Yoon, Jeong-Won;Yoon, Jae-Hyun;Choi, Don-Hyun;Kim, Yong-Il;Jung, Seong-Boo
    • Proceedings of the KWS Conference
    • /
    • 2009.11a
    • /
    • pp.75-75
    • /
    • 2009
  • 연성회로기판은 일반적으로 절연체를 이루는 폴리이미드와 전도체를 이루는 구리로 구성되어 있다. 폴리이미드는 뛰어난 열적 화학적 안정성, 기계적 특성, 공정성 등의 장점으로 인해 연성회로기판의 절연체로서 제안되었지만 전도체를 이루는 구리와의 접합 특성이 우수하지 않기 때문에 많은 연구가 현재까지 진행되고 있고, 그 결과 연성회로기판의 접합 특성에 많은 개선이 이루어짐과 동시에 다양한 공정 방법이 제안되고 있다. 하지만 고온다습한 환경에서 사용될 경우 폴리이미드의 높은 흡습성과, 구리와 seed layer의 산화 문제로 인해 접합 특성이 저하된다는 단점 또한 가지고 있다. 따라서 본 연구를 통해 고온다습한 조건하에서 seed layer가 80Ni/20Cr 합금으로 구성된 연성회로기판의 seed layer의 두께와 시효시간으로 인해 발생하는 접합 신뢰성의 차이를 관찰하였다. 본 연구에서는 두께 25μm의 폴리이미드 위에 각각 100, 200, 300\AA 두께의 80Ni/20Cr의 합금 조성을 가지는 seed layer를 스퍼터링 공정을 통해 형성한 후 전해도금법을 이용하여 8μm 두께의 구리 전도층을 형성하였다. 접합 특성 평가를 위해 ICP 규격에 따라 전도층 패턴을 폭 3.2mm, 길이 230mm로 시편을 제작하여 50.8mm/min의 이송 속도로 각 시편당 8회의 90 peel test를 실시하였다. 또한 85C/85% 항온항습 조건하에서 각각 24, 72, 120, 168시간 동안 시효 처리 후 같은 방법으로 연성회로기판의 접합 특성을 평가하였다. 파면의 형상과 조성을 분석하기 위해 SEM (Scanning electron microscope)과 EDS (Energy-dispersive X-ray spectroscopy)를 사용하였으며, 파면의 조도 측정을 위해 AFM (Atomic force microscope)을 사용하였다. 또한 파면의 잔여물 분석을 위해 EPMA (Energy probe microanalysis)를 사용하였고 계면의 화학적 결합상태를 분석하기 위해 XPS (X-ray photoelectron spectroscopy)를 통해 파면을 분석하였다.

  • PDF

Ductility Evaluation of Heavyweight Concrete Shear Walls with Wire Ropes as a Lateral Reinforcement (와이어로프로 횡보강된 고중량콘크리트 전단벽의 연성평가)

  • Mun, Ju-Hyun;Yang, Keun-Hyeok
    • Journal of the Korea Concrete Institute
    • /
    • v.27 no.3
    • /
    • pp.207-214
    • /
    • 2015
  • This study examined the feasibility of wire ropes as lateral reinforcement at the boundary element of heavyweight concrete shear walls. The spacing of the wire ropes varied from 60 mm to 120 mm at an interval of 30 mm, which produces the volumetric index of the lateral reinforcement of 0.126~0.234. The wire ropes were applied as a external hoop and/or internal cross-tie. Five shear wall specimens were tested to failure under constant axial load and cyclic lateral loads. Test results showed that with the increase of the volumetric index of the lateral reinforcement, the ductility of shear walls tended to increase, whereas the variation of flexural capacity of walls was minimal. The flexural capacity of shear walls tested was slightly higher than predictions determined from ACI 318-11 procedure. The displacement ductility ratio of shear walls with wire ropes was higher than that of shear wall with the conventional mild bar at the same the volumetric index of the lateral reinforcement. In particular, the shear walls with wire rope index of 0.233 achieved the curvature ductility ratio of more than 16 required for high-ductility design.

Fluid Structure Interaction Analysis of Membrane Type LNG CCS Experiencing the Sloshing Impact by Impinging Jet Model (멤브레인형 LNG 화물창의 강도평가를 위해 적용된 분사모델을 이용한 유체구조 연성해석에 관한 연구)

  • Hwang, Se Yun;Lee, Jang Hyun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.28 no.1
    • /
    • pp.71-78
    • /
    • 2015
  • The reliable sloshing assessment methods for LNG CCS(cargo containment system) are important to satisfy the structural strength of the systems. Multiphase fluid flow of LNG and Gas Compressibility may have a large effect on excited pressures and structural response. Impinging jet model has been introduced to simulate the impact of the LNG sloshing and analyze structural response of LNG CCS as a practical FSI(fluid structure interaction) method. The practical method based on fluid structure interaction analysis is employed in order to evaluate the structural strength in actual scale for Mark III CCS. The numerical model is based on an Euler model that employs the CVFEM(control volume based finite element method). It includes the particle motion of gas to simulate not only the interphase interaction between LNG liquid and gas and the impact load on the LNG insulation box. The analysis results by proposed method are evaluated and discussed for an effectiveness of FSI analysis method.

Flexural Behavior of Concrete Filled Seismic Resistant Steel Tubular Columns Subjected to Axial and Cyclic Lateral Load (축력과 반복수평력을 받는 콘크리트 충전 내진 각형강관 기둥의 휨거동 특성)

  • Kim, Byung-Ho;Shim, Hyun-Ju;Choi, Byong-Jeong;Lee, Eun-Taik
    • Journal of Korean Society of Steel Construction
    • /
    • v.23 no.3
    • /
    • pp.317-326
    • /
    • 2011
  • Today there is a growing range of applications for Concrete-Filled Steel Tube (CFT) member because of its superior performance. Ductility estimation test of concrete-filled seismic resistant steel tubular columns, subjected to axial and cyclic lateral load, was carried out in this study. Seismic resistant steel tubes are manufactured using SN400B plates by a two-seam welding at center of the column width for cold press-formed shape plates of two pieces. A total of eight specimens were manufactured and tested with the parameters of width-thickness ratio of steel tubular column, axial load ratio, and loading conditions to act axial and cyclic lateral load two dynamic actuators were used. From test results, flexural strength, deformation capacity, energy dissipation capacity, and ductility behavior of columns were analyzed.

Evaluation of Steel Pull-Out of Reinforced Concrete Beam-Column Joints (철근콘크리트 보-기둥 접합부 철근의 뽑힘 평가)

  • Woo, Jae-Hyun;Park, Jong-Wook;Kim, Byoung-Il;Lee, Jung-Yoon
    • Journal of the Korea Concrete Institute
    • /
    • v.22 no.6
    • /
    • pp.833-841
    • /
    • 2010
  • In this report, the test results of five reinforced concrete beam-column joint subjected to cyclic load are presented. The main purpose of the research is to investigate the influence of the steel pull-out of the beam-column joints to the shear and ductile capacity of the RC beam-column assembles. In addition, the influence of the amount of beam reinforcement to the joint shear and ductile capacity is evaluated. Test results indicate that the yield penetration of steel bar increases as the joint shear strength ratio, Vj1/Vjby decreases. And the slippage of the steel bars are varied according to the region of the beam-column joints. The pull-out of the steel bars of five specimens was almost the same regardless of the joint shear strength ratio, Vj1/Vjby. Because it was affected by not only the yield penetration of steel bar but also the axial elongation in the plastic hinge.

Evaluation of Nonlinear Seismic Performance Using Equivalent Responses of Multistory Building Structures (대표응답을 이용한 건축구조물의 비선형 지진응답 분석 및 내진성능평가)

  • 이동근;최원호
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.5 no.6
    • /
    • pp.65-76
    • /
    • 2001
  • Determination of ductility demand and prediction of nonlinear seismic responses of a structure under the earthquake ground motions have become a very important subject for evaluation of seismic performance in the performance based seismic design. In this study, the system ductility demand and nonlinear seismic responses of the steel moment framed structures by the nonlinear time history analysis are estimated and compared with those obtained from the capacity spectrum method suggested in ATC-40 and proposed method that is an improvement on the capacity spectrum method using the equivalent responses derived directly from a multi degree of freedom system. the adequacy and validity of the proposed method is verified by comparing the results evaluated by the method proposed in this study and the results obtained from method suggested in ATC-40 to the nonlinear seismic responses of the example structures from the nonlinear time history analysis.

  • PDF

Analysis of Structural and Thermal Parameters for Evaluating Fire Resistance of Steel Beams (철골보의 내화시간 평가를 위한 구조 및 열적 변수해석)

  • Park, Han Na;Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
    • /
    • v.21 no.6
    • /
    • pp.609-618
    • /
    • 2009
  • This paper proposes a versatile formula which can be used to evaluate the fire resistant time of steel beams under various design conditions. Towards this end, the key parameters which affect the fire performance of steel beams were first determined through thermo-mechanical considerations, and classified into two groups: structural parameters and thermal parameters. Then the degree of influence of each parameter on the fire performance was investigated through a fully coupled thermo-mechanical analysis up to the occurrence of run-away deflection. The accuracy of the numerical model used was verified using an available full-scale fire test before conducting an extensive parametric analysis. Multiple linear regression analysis was performed to obtain the formula which can be used to predict the fire resistance time of steel beams under various design conditions. The statistical analysis showed that the proposed formula is very robust. The application of the formula in practical fire design under the current code was illustrated in detail. The economy and other advantages of the proposed formula were clearly shown.

Shear Performance Evaluation of the Joint between Hollow Core Slabs (Hollow core 슬래브 간 접합부의 전단저항성능 평가)

  • Hong, Geon-Ho;Baek, Jong-Sam;Park, Hong-Gun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.4
    • /
    • pp.94-101
    • /
    • 2010
  • Recently, the interest of precast concrete is increased for rapid construction in construction fields. Experimental study about the shear performance of the joint between hollow core slabs which have internal core to reduce their weight was performed. Main test variables were thickness of the topping concrete and existence of the wiremesh. Total 8 specimens including 4 in-plane shear and 4 out of plane shear were tested. Test results were analyzed in terms of cracking load, failure load, failure aspect, stiffness and ductility, and compared its design load to develop optimum design details. Test results indicated that the shear performance of the non-shrinkage mortar specimen was similar to that of 30mm thickness topping concrete specimen, and the effect of wiremesh reinforcement did not affect the failure load or stiffness of the specimens but the increase of ductility. And this paper presents the comparison results of the test results and design load to provide the optimum detail of the joint design between the hollow core slabs.