• Title/Summary/Keyword: ratio of slenderness

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Experimental Study on the Behavior of Circular Steel Tube Columns using HSB600 Steel (HSB600 원형강관 기둥의 거동에 대한 실험적 연구)

  • Kim, Sun Hee;Choi, Young Hwan;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.24 no.6
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    • pp.743-751
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    • 2012
  • This paper investigates an experimental behavior of circular columns and beam-columns made of HSB600 high strength steel as a fundamental study to enhance the applicability of HSB steel. The applicability of the current Standard such as KBC and Eurocode 3 is also evaluated. A total of six specimens are fabricated and tested. The main parameters are slenderness ratio(KLe/r = 12, 14, 40, 65), diameter-to-thickness ratio(D/t = 25, 40), and eccentricity ratio(e/D = 0, 0.5). It is drawn from the experiment that both the KBC and Eurocode 3 can be used to predict the strength of circular columns and beam-columns made of HSB600 high strength steel.

Numerical study on buckling of steel web plates with openings

  • Serror, Mohammed H.;Hamed, Ahmed N.;Mourad, Sherif A.
    • Steel and Composite Structures
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    • v.22 no.6
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    • pp.1417-1443
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    • 2016
  • Cellular and castellated steel beams are used to obtain higher stiffness and bending capacity using the same weight of steel. In addition, the beam openings may be used as a pass for different mechanical fixtures such as ducts and pipes. The aim of this study is to investigate the effect of different parameters on both elastic and inelastic critical buckling stresses of steel web plates with openings. These parameters are plate aspect ratio; opening shape (circular or rectangular); end distance to the first opening; opening spacing; opening size; plate slenderness ratio; steel grade; and initial web imperfection. The web/flange interaction has been simplified by web edge restraints representing simply supported boundary conditions. A numerical parametric study has been performed through linear and nonlinear finite element (FE) models, where the FE results have been verified against both experimental and numerical results in the literature. The web plates are subject to in-plane linearly varying compression with different loading patterns, ranging from uniform compression to pure bending. A buckling stress modification factor (${\beta}$-factor) has been introduced as a ratio of buckling stress of web plate with openings to buckling stress of the corresponding solid web plate. The variation of ${\beta}$-factor against the aforementioned parameters has been reported. Furthermore, the critical plate slenderness ratio separating elastic buckling and yielding has been identified and discussed for two steel grades of DIN-17100, namely: ST-37/2 and ST-52/3. The FE results revealed that the minimum ${\beta}$-factor is 0.9 for web plates under uniform compression and 0.7 for those under both compression and tension.

Nonlinear Stability Analysis of Slender Concrete Columns (세장한 콘크리트 기둥의 비선형 안정 해석)

  • 김진근;양주경;김원근
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.80-85
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    • 1992
  • A nonlinear second-order analysis program that properly describes the nonlinear behavior of concrete was developed by using the layering technique. As the slenderness ratio of column is increased, the peaks of P-M curve lie remote from the section interaction diagram for the same eccentricities. But the peaks of P-M curve lie rather close to the section interaction diagram for very large eccentricities. In this study , the effects of compressive strength of concrete, longitudinal steel ratio, and yield strength of steel on second-order moment of concrete columns were analyzed. As the compressive strength of concrete and the yield strength of steel are increased, the ratio of peak axial force to maximum axial strength for concentrically loaded short column( Pu/Po) is decreased. But as the longitudinal steel ratio is increased, the ratio , Pu/Po increases.

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Free Vibrations of Circular Curved Beams with Constant Volume (일정체적 원호형 곡선보의 자유진동)

  • Lee, Byoung-Koo;Lee, Tae-Eun;Choi, Jong-Min;Park, Chang-Eun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.6
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    • pp.570-579
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    • 2011
  • This paper deals with free vibrations of the circular curved beams with constant volume, whose cross sectional shapes are the circular solid cross-sections. Volumes of the objective beam are always held in constant regardless shape functions of the cross-sectional radius. The shape functions are chosen as the linear, parabolic and sinusoidal ones. Ordinary differential equations governing free vibrations of such beam are derived and solved numerically for determining the natural frequencies. In numerical examples, the hinged-hinged, hinged-clamped and clamped-clamped end constraints are considered. As the numerical results, relationships between frequency parameters and various beam parameters such as rise ratio, section ratio, elasticity ratio, volume ratio, slenderness ratio and taper type are reported in tables and figures.

Development of Design Formula for Predicting Post-Buckling Behaviour and Ultimate Strength of Cylindrical Shell

  • Lee, Jung-Ho;Oh, Young-Cheol;Seo, Kwang-Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.3
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    • pp.313-319
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    • 2017
  • Cylindrical shells are often used in ship structures at deck plating with a camber, side shell plating at fore and aft parts, and bilge structure part. It has been believed that such curved shells can be modelled fundamentally by a part of a cylinder under axial compression. From the estimations with the usage of cylinder models, it is known that, in general, curvature increases the buckling strength of a curved shell subjected to axial compression, and that curvature is also expected to increase the ultimate strength. We conduct series of elasto-plastic large deflection analyses in order to clarify the fundamentals in buckling and plastic collapse behaviour of cylindrical shells under axial compression. From the numerical results, we derive design formula for predicting the ultimate strength of cylindrical shell, based on a series of the nonlinear finite element calculations for all edges, simply supporting plating, varying the slenderness ratio, curvature and aspect ratio, as well as the following design formulae for predicting the ultimate strength of cylindrical shell. From a number of analysis results, fitting curve can be developed to use parameter of slenderness ratio with implementation of the method of least squares. The accuracy of design formulae for evaluating ultimate strength has been confirmed by comparing the calculated results with the FE-analysis results and it has a good agreement to predict their ultimate strength.

Experimental Evaluation of Flexural Performance Evaluation of Tapered H-Section Beams with Slender Web (춤이 큰 웨브 변단면 H형 보의 휨내력에 대한 실험적 평가)

  • Shim, Hyun Ju;Lee, Seong Hui;Kim, Jin Ho;Lee, Eun Taik;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.19 no.5
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    • pp.483-492
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    • 2007
  • Pre-Engineering Building (PEB) system is one of the most economical structural systems. Tapered members can resist a maximum stress at a single location, whereas stresses of the rest of the members are considerably low. This results in appreciable savings both in terms of materials and construction costs. However, it was appreciated that special consideration would be required for certain aspects of this structural form. In particular, because of their slenderness, webs would buckle laterally and torsionally under the combined action of excessive axial, bending and shear forces. In this study, a total of four large-scale rafters with simple ends were tested. The main parameters were the width-thickness ratio of the web, the stiffener, and the flange brace. The purpose of this experiment is to evaluate the structural stability and to offer back-data on PEB design.

RC Flat Plate Subject to Combined In-Plane Compressive and Out-of-Plane Floor Loads (면내 압축력 및 면외 바닥하중을 받는 플랫 플레이트 슬래브)

  • Park, Hong-Gun
    • Magazine of the Korea Concrete Institute
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    • v.11 no.1
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    • pp.231-242
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    • 1999
  • This paper presents a numerical study on the flat plates in deep basements, subjected to out-of-plane floor load and in-plane compressive load due to soil and hydraulic lateral pressure. For nonlinear finite element analysis, a computer program addressing material and geometric nonlinearities is developed. The validity of the numerical model is established by comparison with existing experiments performed on plates simply supported on four edges. The flat plates to be studied are designed according to the Direct Design Method in Korean Building Code for Structural Concrete. Through numerical study on the effects of different load combinations and loading sequence, the load condition that governs the strength of the flat plates is determined. For the plates under the governing load condition, parametric studies are performed to investigate variations of the strength with reinforcement ratio, aspect ratio, concrete strength, and slenderness ratio. Based on the numerical results, the floor load magnification factor is proposed.

Seismic performances of steel reinforced concrete bridge piers

  • Deng, Jiangdong;Liu, Airong;Yu, Qicai;Peng, Guoxing
    • Steel and Composite Structures
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    • v.21 no.3
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    • pp.661-677
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    • 2016
  • The quasi static test of the steel reinforced concrete (SRC) bridge piers and rigid frame arch bridge structure with SRC piers was conducted in the laboratory, and the seismic performance of SRC piers was compared with that of reinforced concrete (RC) bridge piers. In the test, the failure process, the failure mechanism, hysteretic curves, skeleton curves, ductility coefficient, stiffness degradation curves and the energy dissipation curves were analyzed. According to the $M-{\Phi}$ relationship of fiber section, the three-wire type theoretical skeleton curve of the lateral force and the pier top displacement was proposed, and the theoretical skeleton curves are well consistent with the experimental curves. Based on the theoretical model, the effects of the concrete strength, axial compression ratio, slenderness ratio, reinforcement ratio, and the stiffness ratio of arch to pier on the skeleton curve were analyzed.

Free Vibration Analysis of Arches with Thickness varying in a Discontinuous Fashion (불연속 변화단면 아치의 자유진동 해석)

  • 이병구;오상진;모정만;김현상
    • Journal of KSNVE
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    • v.3 no.4
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    • pp.331-339
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    • 1993
  • The main purpose of this paper is to present an analytical method for free vibration of arches with thickness varying in a discontinuous fashion. The ordinary differential equations governing the free vibration of these arches are derived as nondimensional forms including the effect of rotatory inertia. The governing equation are solved numerically for the circular and sinusoidal arches with hinged-hinged-hinged end clamped-clamped end constraints. As the numerical results, the effect of rotatory inertia on the natural frequencies is reported. The lowest four natural frequencies are presented as the functions of four nondimensional system parameters; the rise to span length ratio, the slenderness ratio, the section ratio and the ratio of discontinuous section.

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Experimental and numerical analyses on axial cyclic behavior of H-section aluminium alloy members

  • Wu, Jinzhi;Zheng, Jianhua;Sun, Guojun;Chang, Xinquan
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.11-28
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    • 2022
  • This paper considers the combination of cyclic and axial loads to investigate the hysteretic performance of H-section 6061-T6 aluminum alloy members. The hysteretic performance of aluminum alloy members is the basis for the seismic performance of aluminum alloy structures. Despite the prevalence of aluminum alloy reticulated shells structures worldwide, research into the seismic performance of aluminum alloy structures remains inadequate. To address this deficiency, we design and conduct cyclic axial load testing of three H-section members based on a reliable testing system. The influence of slenderness ratios and bending direction on the failure form, bearing capacity, and stiffness degradation of each member are analyzed. The experiment results show that overall buckling dominates the failure mechanism of all test members before local buckling occurs. As the load increases after overall buckling, the plasticity of the member develops, finally leading to local buckling and fracture failure. The results illustrate that the plasticity development of the local buckling position is the main reason for the stiffness degradation and failure of the member. Additionally, with the increase of the slenderness ratio, the energy-dissipation capacity and stiffness of the member decrease significantly. Simultaneously, a finite element model based on the Chaboche hybrid strengthening model is established according to the experiment, and the rationality of the constitutive model and validity of the finite element simulation method are verified. The parameter analysis of twenty-four members with different sections, slenderness ratios, bending directions, and boundary conditions are also carried out. Results show that the section size and boundary condition of the member have a significant influence on stiffness degradation and energy dissipation capacity. Based on the above, the appropriate material constitutive relationship and analysis method of H-section aluminum alloy members under cyclic loading are determined, providing a reference for the seismic design of aluminum alloy structures.