• Title/Summary/Keyword: column flexural stiffness

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Evaluation of Punching Shear Safety of a Two-Way Void Plywood Slab System with Form (거푸집 패널이 부착된 2방향 중공슬래브의 뚫림 전단 안전성 평가)

  • Hur, Moo-Won;Woo, Hyung-Sik;Park, Jung-Min;Kang, Hyun-Wook;Park, Tae-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.5
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    • pp.182-189
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    • 2021
  • VPS(Void Plywood Slab System, VPS) has optimized the shape of the hollow material. In addition, it has a function to prevent the floating of the hollow material and the separation due to the working load. In this study, the punching shear capacity of flat plate was performed using Void Plywood Slab System with form work panel proposed in the previous study. As a result of the test, the strength of the VSPS specimen in which the hollow material was placed beyond 2.0 times the column width from the loading point was reduced by 9.4% compared to the reference specimen. However, the strength value was about 1.57 times higher than the design value suggested by KBC 2016. It was found that there was no change in stiffness compared to the reference specimen until shear failure occurred in the VSPS specimen in which the hollow material was placed. It can be seen that this experiment is being destroyed by shear as the flexural reinforcing bars are sufficiently reinforced.

Dynamic Behaviour of Masonry inFilled Reinforced Concrete Frames with Non-Seismic Details (진동대실험을 통한 비내진상세를 가지는 RC 골조의 조적채움벽 유무에 따른 동적 거동 평가)

  • Baek, Eun-Rim;Kim, Kyung-Min;Cheon, Ju-Hyun;Oh, Sang-Hoon;Lee, Sang-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.121-129
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    • 2017
  • In this paper, the shake table test for the masonry infilled reinforced concrete frame with non-seismic details was carried out in order to evaluate its dynamic behaviour and damage under seismic condition. The tested specimens were the RC frame and the masonry infilled RC frame and the dynamic characteristics, such as a resonant period, acceleration response, displacement response and base shear force response, were compared between them. As a result of the shake table test, RC frame specimen had flexural cracks at the top and bottom of the column and shear cracks at the joints. In the case of masonry infilled RC frame, the damage of the frame was relatively minor but the sliding cracks and diagonal shear cracks on the masonry wall were severe at the final excitation. The resonant period of infilled RC frame specimen was shorter than that of the RC frame specimen because the masonry infill contributed to increase the stiffness. The maximum displacement response of the infilled RC frame specimen was decreased by about 20% than the RC frame specimen. It was analyzed that the masonry infill wall applied in this study contributed to increase the lateral strength of the RC frame with non - seismic detail by about 2.2 times and the stiffness by about 1.6 times.

Large Deformational Elasto-Plastic Analysis of Space Frames Considering Finite Rotations and Joint Connection Properties (유한회전과 접합부 특성을 고려한 공간프레임의 대변형 탄소성 해석)

  • Lee, Kyung Soo;Han, Sang Eul
    • Journal of Korean Society of Steel Construction
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    • v.21 no.6
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    • pp.597-608
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    • 2009
  • In this paper, large-deformation elasto-plastic analysis of space frames that considersjoint connection properties is presented. This method is based on the large-deformation formula with finite rotation, which was developed initially for elastic systems, and is extended herein to include the elasto-plastic effect and the member joint connection properties of semi-rigid what?. The analytical method was derived from the Eulerian concept, which takes into consideration the effects of large joint translations and rotations. The localmember force-deformation relationships were obtained from the beam-column approach, and the change caused by the axial strain in the member chord lengths and flexural bowing were taken into account. The effect of the axial force of the member on bending and torsional stiffness, and on the plastic moment capacity, is included in the analysis. The material is assumed to be ideally elasto-plastic, and yielding is considered concentrated at the member ends in the form of plastic hinges. The semi-rigid properties of the member joint connection are considered based on the power or linear model. The arc length method is usedto trace the post-buckling range of the elastic and elasto-plastic problems with the semi-rigid connection. A sample non-linear buckling analysis was carried out with the proposed space frame formulations to demonstrate the potential of the developed method in terms of its accuracy and efficiency.

Calculations of Flat Plate Deflections Considering Effects of Construction Loads and Cracking (시공하중 및 균열 효과를 고려한 플랫 플레이트의 처짐 산정)

  • Kim, Jae-Yo;Im, Ju-Hyeuk;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.21 no.6
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    • pp.797-804
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    • 2009
  • The structural designs of RC flat plates that have insufficient flexural stiffness due to lack of support from boundary beams may be governed by serviceability as well as a strength criteira. Specially, since over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction, a construction sequence and its impact on the slab deflections may be decisive factors in designs of flat plate systems. In this study, the procedure of calculating slab deflections considering construction sequences and concrete cracking effects is proposed. The construction steps and the construction loads are defined by the simplified method, and then the slab moments, elastic deflections, and the effective moment of inertia are calculated in each construction step. The elastic deflections in column and middle strips are magnified to inelastic deflections by the effective moment of inertia, and the center deflection of slab are calculated by the crossing beam method. The proposed method is verified by comparisons with the existing test result and the nonlinear analysis result. Also, by applications of the proposed method, the effects of the slab construction cycle and the number of shored floors on the deflections of flat plates under construction are analyzed.