• Title, Summary, Keyword: rectangular walls

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Effects of High-Strength Concrete Shear Walls with Rectangular Steel Tubes (고강도 콘크리트 전단벽체에 사용된 각형강관의 효과)

  • Kim, Myung-Jun;Oh, Jong-Han;Cho, Soon-Ho;Choi, Ki-Bong;Cho, Chul-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.2
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    • pp.209-217
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    • 1998
  • Compared to normal-strength concrete, high-strength concrete has the lower lateral expansion capacity caused by the higher elastic modulus and the lower internal crack characteristic. Therefore, the effect of the lateral confining action of hoops appears slowly. Nevertheless, it has been reported that the strength and deformation capacity of high-strength concrete is improved by well-distributed hoops. Due to that argument, this investigation has been compared and analyzed by the experimental works on the deformation capacity and the confinement mechanism of high-strength concrete shear wall of the high-rise building reinforced by rectangular steel tubes and rectangular hoops at both edges. It is suggested that, using high-strength concrete($500kgf/cm^2$, $700kgf/cm^2$), hoops should be replaced with rectangular steel tubes in order to prevent closely spaced hoops at the edge of the shear wall.

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Heat Transfer and Friction in Rectangular Convergent Channels with Ribs on One Wall

  • Kim, Won-Cheol;Lee, Myung-Sung;Bae, Sung-Taek;Ahn, Soo-Whan
    • Journal of the Korea Society For Power System Engineering
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    • v.18 no.2
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    • pp.12-18
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    • 2014
  • The local heat transfer of developed turbulent flows in the stationary ribbed rectangular convergent channels has been investigated experimentally. The rectangular convergent channels with one ribbed surface only have the inclination of $0.72^{\circ}$ and $1.43^{\circ}$ at which the ribbed wall is manufactured with a fixed rib height (e) of 10 mm and the ratio of rib spacing (p) to height (e) =10. The measurement was conducted within the range of Reynolds numbers from 15,000 to 89,000. The local heat transfer characteristics of the rectangular convergent channels are quite different from those of the ribbed square straight channel.

Hydrodynamic pressures acting on the walls of rectangular fluid containers

  • Dogangun, Adem;Livaoglu, Ramazan
    • Structural Engineering and Mechanics
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    • v.17 no.2
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    • pp.203-214
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    • 2004
  • The dynamic response characteristics of a rectangular fluid container are investigated by using finite element method. The fluid is assumed to be linear-elastic, inviscid and compressible. A displacement-based fluid finite element was employed to allow for the effects of the fluid. A typical rectangular fluid container, which is used in recent studies, is considered for the numerical analysis. The North-South component of El Centro Earthquake records is used as input ground acceleration. Rigid and flexible fluid containers solutions are obtained for the chosen sample tank. Hydrodynamic pressures and sloshing motions are determined using Lagrangian fluid finite element. The results obtained from this study are compared with the results obtained by boundary-finite element method (BEM-FEM) and requirements of Eurocode-8. Based on the numerical analysis, some conclusions and discussions on the design considerations for rectangular fluid containers are presented.

Pushover Analysis of Reinforced Concrete Shear Wall Subjected to High Axial Load Using Fiber Slices and Inelastic Shear Spring (섬유(Fiber)요소와 비선형 전단스프링을 적용한 고축력을 받는 철근콘크리트 전단벽의 비선형거동 분석)

  • Jun, Dae Han
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.5
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    • pp.239-246
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    • 2015
  • Reinforced concrete shear walls are effective for resisting lateral loads imposed by wind or earthquakes. Observed damages of the shear wall in recent earthquakes in Chile(2010) and New Zealand(2011) exceeded expectations. Various analytical models have been proposed in order to incorporate such response features in predicting the inelastic response of RC shear walls. However, the model has not been implemented into widely available computer programs, and has not been sufficiently calibrated with and validated against extensive experimental data at both local and global response levels. In this study, reinforced concrete shear walls were modeled with fiber slices, where cross section and reinforcement details of shear walls can be arranged freely. Nonlinear analysis was performed by adding nonlinear shear spring elements that can represent shear deformation. This analysis result will be compared with the existing experiment results. To investigate the nonlinear behavior of reinforced concrete shear walls, reinforced concrete single shear walls with rectangular wall cross section were selected. The analysis results showed that the yield strength of the shear wall was approximately the same value as the experimental results. However, the yielding displacement of the shear wall was still higher in the experiment than the analysis. The analytical model used in this study is available for the analysis of shear wall subjected to high axial forces.

Comparative in-plane pushover response of a typical RC rectangular wall designed by different standards

  • Dashti, Farhad;Dhakal, Rajesh P.;Pampanin, Stefano
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.667-689
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    • 2014
  • Structural walls (also known as shear walls) are one of the common lateral load resisting elements in reinforced concrete (RC) buildings in seismic regions. The performance of RC structural walls in recent earthquakes has exposed some problems with the existing design of RC structural walls. The main issues lie around the buckling of bars, out-of plane deformation of the wall (especially the zone deteriorated in compression), reinforcement getting snapped beneath a solitary thin crack etc. This study compares performance of a typical wall designed by different standards. For this purpose, a case study RC shear wall is taken from the Hotel Grand Chancellor in Christchurch which was designed according to the 1982 version of the New Zealand concrete structures standard (NZS3101:1982). The wall is redesigned in this study to comply with the detailing requirements of three standards; ACI-318-11, NZS3101:2006 and Eurocode 8 in such a way that they provide the same flexural and shear capacity. Based on section analysis and pushover analysis, nonlinear responses of the walls are compared in terms of their lateral load capacity and curvature as well as displacement ductilities, and the effect of the code limitations on nonlinear responses of the different walls are evaluated. A parametric study is also carried out to further investigate the effect of confinement length and axial load ratio on the lateral response of shear walls.

A theoretical study on the factors for the seismic performance of RC T-shaped walls (철근콘크리트 T형 벽체의 내진성능 영향인자에 관한 해석적 연구)

  • 하상수;최창식;오영훈;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.521-526
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    • 2002
  • The seismic performance of structural walls subjected to the cyclic lateral loads are influenced by various factors, like sectional shape, aspect ratio, reinforcement ratio, arrangement of reinforcement, and axial load ratio etc. In this research, reinforced concrete structural walls with the T-shaped cross section were selected. The seismic performance of T-shaped wall was affected by the many (actors because T-shaped wall is irregular wall composed to two rectangular walls. Especially the seismic performance of T-shaped wall varies with the flange condition and the various factors including the flange condition were determined. Therefore, the objective of this study is to understand the factors to improve seismic performance of RC T-shaded tv using sectional analysis.

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Characteristics of Heat Transfer in the Ribbed Rectangular Channel with Variable Heating Condition

  • Kim Won-Cheol;Putra Ary Bachtiar Krishna;Kang Ho-Keun;Ahn Soo-Whan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.15 no.1
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    • pp.10-16
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    • 2007
  • Surface heat transfer of a fully developed turbulent air flow in a $45^{\circ}$ inclined ribbed square duct with two and four heating walls was experimentally investigated, at which the experimental works were performed for Reynolds numbers ranging from 7,600 to 24,900. The pitch-to-rib height ratio, p/e was kept at 8 and rib-height-to-channel hydraulic diameter ratio, $e/D_h$ was kept at 0.0667. The channel length-to-hydraulic diameter ratio, $L/D_h$ was 60. The heat transfer coefficient values were decreased with the increase in the number of heating walls. Results of this investigation could be used in various applications of internal channel turbulent flow involving roughened walls.

Analysis of the False Diffusion Effects in Numerical Simulation of Diesel Spray Impinging on Inclined Walls (경사진 벽충돌 디젤 분무에 대한 수치해석에서 오류확산이 미치는 영향)

  • Gwon, H.R.;Lee, S.H.
    • Journal of ILASS-Korea
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    • v.13 no.1
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    • pp.22-27
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    • 2008
  • The false diffusion occurs generally when the flow is oblique to the grid lines and when there is a non-zero gradient of the dependent variable in the direction normal to the flow. This numerical problem can overestimate diffusion terms in the continuous phase, causing the numerical inaccuracy for the simulation of impinging sprays on inclined walls because most of spray calculation uses rectangular grid system. Therefore, the main objective of this article is to investigate numerically the influence of false diffusion on numerical simulation for spray-wall impingement on inclined walls. It is found that unlike the spray impingement normal to the wall, the numerical diffusion exists in the case when diesel sprays impinge on the inclined walls with different angles. The results show that the correction function should be considered for accurate prediction of spray penetration length and more elaborate numerical schemes should be utilized to reduce the false diffusion.

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Modelling seismically repaired and retrofitted reinforced concrete shear walls

  • Cortes-Puentes, W. Leonardo;Palermo, Dan
    • Computers and Concrete
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    • v.8 no.5
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    • pp.541-561
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    • 2011
  • The Finite Element Method (FEM) was employed to demonstrate that accurate simulations of seismically repaired and retrofitted reinforced concrete shear walls can be achieved provided a good analysis program with comprehensive models for material and structural behaviour is used. Furthermore, the analysis tool should have the capability to retain residual damage experienced by the original structure and carry it forward in the repaired and retrofitted structure. The focus herein is to provide quick, simple, but reliable modelling procedures for repair and retrofitting strategies such as concrete replacement, addition of diagonal reinforcing bars, bolting of external steel plates, and bonding of external steel plates and fibre reinforced polymer sheets, thus illustrating versatility in the modelling. Slender, squat, and slender-squat shear walls were investigated. The modelling utilized simple rectangular membrane elements for the concrete, truss bar elements for the steel and FRP retrofitting materials, and bond-link elements for the bonding interface between steel or FRP to concrete. The analyses satisfactorily simulated seismic behaviour, including lateral load capacity, displacement capacity, energy dissipation, hysteretic response, and failure mode.

Ductility Design of Structural Wall (RC 구조벽의 연성설계)

  • Kang Su Min;Park Hong Gun;Kim Ook Jong;Lee Do Bum
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.353-356
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    • 2004
  • Nonlinear numerical analysis was performed to investigate the behavioral characteristics and failure mechanism of flexure -dominated structural walls with partially confined boundary elements. Based on the results, deformability of walls with partially confined boundary elements was evaluated, and a design method which can determine depth of confined boundary element according to given ductility demand, was developed. Also, effective details of laterally confining re-bars were proposed for boundary elements with rectangular cross-section. The design method can be used to choose the spacing of confining re-bars assuring the confining effect and constructability.

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