• 제목/요약/키워드: bending-carrying capacity

검색결과 114건 처리시간 0.021초

Flexural studies on reinforced geopolymer concrete beams under pure bending

  • Sreenivasulu, C.;Jawahar, J. Guru;Sashidhar, C.
    • Advances in concrete construction
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    • 제8권1호
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    • pp.33-37
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    • 2019
  • The present investigation is mainly focused on studying the flexural behavior of reinforced geopolymer concrete (RGPC) beams under pure bending. In this study, copper slag (CS) was used as a partial replacement of fine aggregate. Sand and CS were blended in different proportions (100:0, 80:20, 60:40 and 40:60) (sand:CS) by weight. Fly ash and ground granulated blast furnace slag (GGBS) were used as binders and combination of sodium hydroxide (8M) and sodium silicate solution were used for activating the binders. The reinforcement of RGPC beam was designed as per guidelines given in the IS 456-2000 and tested under pure bending (two-point loading) after 28 days of ambient curing. After conducting two point load test the flexural parameters viz., moment carrying capacity, ultimate load, service load, cracking moment, cracking load, crack pattern and ultimate deflection were studied. From the results, it is concluded that RGPC beams have shown better performance up to 60% of CS replacement.

축방향 압축력을 받는 원통형 박막소재의 좌굴후 탄소성 대변형에 관한 실험 및 해석 연구 (Experimental and Numerical Study on the Elastic-Plastic, Large Deflection, Post-Buckling Behavior of Axially Compressed Circular Cylindrical Tubes)

  • 권세문;윤희도
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.969-974
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    • 2001
  • Circular cylindrical tubes are widely used in structures such as vehicles and aircraft structures, where light weight and high compressive/bending/torsional load carrying capacity are required. When axially compressed, relatively thick circular cylindrical tubes deform in a so-called ring mode. Each ring develops and completely collapses one by one until the entire length of the tube collapses. During the collapse process the tube absorbs a large amount of energy. Like honey-comb structures, circular cylindrical tubes are light weighted, are capable of high axial compressive load, and absorb a large amount of energy before being completely collapsed. In this report, the subject of axial plastic buckling of circular cylindrical tubes was reviewed first. Then, the axial collapse process of the tubes in a so-called ring mode was studied both experimentally and numerically. In the experiment, steel tubes were axially compressed slowly until they were completely collapsed. Fixed boundary condition was provided. Numerical study involves axisymmetric, elastic-plastic, large deflection, self-contact mechanisms. The measured and calculated results were presented and compared with each other. The purpose of the study was to evaluate the load carrying capacity and the energy absorbing capacity of the tube.

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Seismic performance of precast joint in assembled monolithic station: effect of assembled seam shape and position

  • Liu, Hongtao;Du, Xiuli
    • Earthquakes and Structures
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    • 제17권6호
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    • pp.611-621
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    • 2019
  • Precast concrete structure has many advantages, but the assembled seam will affect potentially the overall seismic performance of structure. Based on the sidewall joint located in the bottom of assembled monolithic subway station, the main objectives of this study are, on one hand to present an experimental campaign on the seismic behavior of precast sidewall joint (PWJ) and cast-in-place sidewall joint (CWJ) subjected to low-cycle repeated loading, and on the other hand to explore the effect of shape and position of assembled seam on load carrying capacity and crack width of precast sidewall joint. Two full-scale specimens were designed and tested. The important index of failure pattern, loading carrying capacity, deformation performance and crack width were evaluated and compared. Based on the test results, a series of different height and variably-shape of assembled seam of precast sidewall joint were considered. The test and numerical investigations indicate that, (1) the carrying capacity and deformation capacity of precast sidewall and cast-in-place sidewall were very similar, but the crack failure pattern, bending deformation and shearing deformation in the plastic hinge zone were different obviously; (2) the influence of the assembled seam should be considered when precast underground structures located in the aquifer water-bearing stratum; (3) the optimal assembled seam shape and position can be suggested for the design of precast underground concrete structures according to the analysis results.

Flexural behaviour of fully concrete encased steel castellated section with different configuration of openings

  • G. Velrajkumar;M.P. Muthuraj
    • Advances in concrete construction
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    • 제17권5호
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    • pp.273-284
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    • 2024
  • The steel-concrete composite system has been playing a vital role in the construction sector for the past two decades. By using steel and concrete together, we achieve strong load resistance with minimal deflection and bending stress. The study focuses on the numerical and analytical behaviour of concrete encased steel castellated beams and compared them with previous experiments. The study used five composite beams, including one control reinforced concrete beam (CC), one fully concrete encased steel beam (FCES), and three fully concrete encased castellated beams. The major variable is the opening configuration of the castellated beam, such as openings along the longitudinal axis, above the longitudinal axis, and below the longitudinal axis. The 150 mm × 250 mm cross section and 2000 mm in length of beams were used. Using the finite element software ANSYS, we conduct nonlinear finite element analysis for the entire beam and compare it with test data. The numerical load carrying capacity of concrete encased steel castellated beam with a hexagonal opening above the longitudinal axis (FCESCB H2) is 160 kN is closer to the experimental observation. Von Mises strain of FCESB is 0.004232, which is lower than CB and composite castellated beam. The ductility factor and energy absorption capacity of FCESB are 5.090 and 1688.47 kNm. It was observed that the configuration of the opening will influence the strength of the composite beam. Plastic moment methods were employed to estimate the ultimate load carrying capacity of the beam. In the analytical study the beams were assumed as perfectly plastic. The ultimate analytical load carrying capacity of FCESCB H2 is 21.87% higher than FCESB. It found that performing FCESCB H2 is superior to the entire specimen.

동력분배용 중간변속기 개발에 관한 연구 (Development of the Transfer Case for Power Distribution)

  • 심기중;문홍주;이영춘
    • 한국기계가공학회지
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    • 제17권2호
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    • pp.95-102
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    • 2018
  • This paper presents the development of the transfer case for a 3.5-ton commercial vehicle. A transfer case is composed of many parts, including helical gear, shaft, bearing, planetary gear, and others. Helical gears are currently used as power transmitting gears due to their relatively smooth and silent operation, large load carrying capacity, and operation at higher speeds. The key parameter in transfer case development is the bending stress at the root of a tooth in the helical gear. The bending stress of the helical gear has been studied through theoretical calculation and finite element method (FEM) analysis. Major factors of the bending stress calculation are determined according to American Gear Manufacturers Association (AGMA) standards, and FEM model analysis of the helical gear is conducted. FEM results are compared with theoretical calculations and the difference of the bending stress is described.

발포 Al5Si4Cu4Mg 알루미늄 합금이 충진된 304 스테인리스강 원통의 굽힘저항 특성 (Bending Behaviors of Stainless Steel Tube Filled with Al5Si4Cu4Mg Closed Cell Aluminum Alloy Foam)

  • 김엄기;이효진;조성석
    • 대한기계학회논문집A
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    • 제27권10호
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    • pp.1686-1694
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    • 2003
  • The foam-filled tube beams can be used for the front rail and firewall structures to absorb impact energy during frontal or side collision of vehicles. In the case of side collision where bending is involved in the crushing mechanism, the foam filler would be effective in maintaining progressive crushing of the thin-walled structures so that much impact energy could be absorbed. In this study, bending behaviors of the closed-cell-aluminum-alloy-foam-filled stainless steel tube were investigated. The various foam-filled specimens including piecewise fillers were prepared and tested. The aluminum-alloy-foam filling offered the significant increase of bending resistance. Their suppression of the inward fold formation at the compression flange as well as the multiple propagating folds led to the increase of load carrying capacity of specimens. Moreover, the piecewise foams would provide the easier way to fill the thin-walled shell structures without the drawback of strength.

Brazier effect of single- and double-walled elastic tubes under pure bending

  • Sato, Motohiro;Ishiwata, Yuta
    • Structural Engineering and Mechanics
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    • 제53권1호
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    • pp.17-26
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    • 2015
  • The cross sections of hollow cylindrical tubes ovalise under a pure bending condition, and this reduces their flexural stiffness as their curvatures increase. It is important to accurately evaluate this phenomenon, known as the 'Brazier effect', to understand the bending behaviour of the systems considered. However, if the tubes are supported by an elastic medium or foundation, the ovalisation displacements of their cross sections may decrease. From this point of view, the purpose of this research is to analytically investigate the bending characteristics of single- and double-walled elastic tubes contacted by an elastic material by considering the Brazier effect. The Brazier moment, which is the maximum moment-carrying capacity of the ovalised cross section, can be calculated by introducing the strain energy per unit length of the tube in terms of the degree of ovalisation for the tube and the curvature. The total strain energy of the double-walled system is the sum of the strain energies of the outer and inner tubes and that of the compliant core. Results are comparatively presented to show the variation in the degree of ovalisation and the Brazier moment for single- and double-walled tubes.

단조 하중을 받는 고강도 철근 콘크리트 기둥의 비탄성 거동에 관한 시험적 연구 (An Experimental Study On the Inelastic Behavior of the High Strength Reinforced Concrete Column subject to Monotonic Loads)

  • 정세환;정하선;김상식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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    • pp.53-58
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    • 1992
  • This research is related to the experimental investigation of the inelastic behavior of R/C columns with high strength concrete. A total of eight specimens have been tested with different span ratios, steel reinforcements and load applications. Through tests bending moments were applied incrementally while axial forces being kept constantly at 80 tons. Careful observation were given to initial crack formation, crack patterns and propagation paths. Comparative studies have been made on the load carrying capacity for R/C columns with high strength concrete versus normal strength concrete.

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Flexural behaviour of reinforced concrete beams strengthened with NSM CFRP prestressed prisms

  • Liang, Jiong-Feng;Yu, Deng;Xie, Shengjun;Li, Jianping
    • Structural Engineering and Mechanics
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    • 제62권3호
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    • pp.291-295
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    • 2017
  • The behaviour of reinforced concrete beams strengthened with near surface mounted (NSM) CFRP prestressed prisms was experimentally investigated. Five RC beams were tested under four point bending. All beams were made with dimensions of 300 mm in width, 2000 mm in length and 150 in depth. The effects of presstress level of CFRP prestressed prisms and prism material type were studied. The failure mode, load capacity, deflection, CFRP strain, steel strain and ductility of the tested beams were all analyzed. The results showed that the behavior of the reinforced concrete beams strengthened with NSM CFRP prestressed prisms showed a significant increase in the load-carrying capacity and the deformation capacity. The NSM CFRP prestressed prisms strengthening technique could be considered as an effective method for repairing RC structures.

Ultra-low cycle fatigue tests of Class 1 H-shaped steel beams under cyclic pure bending

  • Zhao, Xianzhong;Tian, Yafeng;Jia, Liang-Jiu;Zhang, Tao
    • Steel and Composite Structures
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    • 제26권4호
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    • pp.439-452
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    • 2018
  • This paper presents experimental and numerical study on buckling behaviors and hysteretic performance of Class 1 H-shaped steel beam subjected to cyclic pure bending within the scope of ultra-low cycle fatigue (ULCF). A loading device was designed to achieve the pure bending loading condition and 4 H-shaped specimens with a small width-to-thickness ratio were tested under 4 different loading histories. The emphasis of this work is on the impacts induced by local buckling and subsequent ductile fracture. The experimental and numerical results indicate that the specimen failure is mainly induced by elasto-plastic local buckling, and is closely correlated with the plastic straining history. Compared with monotonic loading, the elasto-plastic local buckling can occur at a much smaller displacement amplitude due to a number of preceding plastic reversals with relative small strain amplitudes, which is mainly correlated with decreasing tangent modulus of the material under cyclic straining. Ductile fracture is found to be a secondary factor leading to deterioration of the load-carrying capacity. In addition, a new ULCF life evaluation method is proposed for the specimens using the concept of energy decomposition, where the cumulative plastic energy is classified into two categories as isotropic hardening and kinematic hardening correlated. A linear correlation between the two energies is found and formulated, which compares well with the experimental results.