• Title/Summary/Keyword: Slenderness

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Axial load-strain relationships of partially encased composite columns with H-shaped steel sections

  • Bangprasit, Papan;Anuntasena, Worakarn;Lenwari, Akhrawat
    • Steel and Composite Structures
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    • v.45 no.1
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    • pp.51-66
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    • 2022
  • This paper presents the axial compression behavior of partially encased composite (PEC) columns using H-shaped structural steel. In the experimental program, a total of eight PEC columns with H-shaped steel sections of different flange and web slenderness ratios were tested to investigate the interactive mechanism between steel and concrete. The test results showed that the PEC columns could sustain the load well beyond the peak load provided that the flange slenderness ratio was not greater than five. In addition, the previous analytical model was extended to predict the axial load-strain relationships of the PEC columns with H-shaped steel sections. A good agreement between the predicted load-strain relationships and test data was observed. Using the analytical model, the effects of compressive strength of concrete (21 to 69 MPa), yield strength of steel (245 to 525 MPa), slenderness ratio of flange (4 to 10), and slenderness ratio of web (10 to 25) on the interactive mechanism (Kh = confinement factor for highly confined concrete and Kw = reduction factor for steel web) and ductility index (DI = ratio between strain at peak load and strain at proportional load) were assessed. The numerical results showed that the slenderness of steel flange and yield strength of steel significantly influenced the compression behavior of the PEC columns.

Experiments on Second -Order Behavior of High Strength Concrete Columns (고강도 콘크리트 기둥의 2계 거동에 관한 실험적 연구)

  • 김진근;양주경
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.167-172
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    • 1992
  • To analyze the effects compressive strength of concrete and longitudinal steel ratio on second-order moment of columns, 30tied rein reinforced concrete columns with hinged ends were tested. The 80mm square cross section was used and the amount of eccentricity was 24mm. The compressive strengths of column specimens with slenderness ratios of 10, 60, and 100were 250, 648 and 880kg/$\textrm{cm}^2$, and the longitudinal steel ratios were 1.98%(4-D6) and 3.95%(8-D6). The ratio of ultimate load capacity to that of short column with the same eccentricity (Pu/Pn) was much decreased at high slenderness ratio with increasing the compressive strength of concrete. And the lateral displacement of slender column at the ultimate load was decreased as the strength was increased. These are due to that at high slenderness ratio the load capacity and behavior of column are affected by flexural rigidity. And, it was also found that with increasing steel ratio, the value of Pu/Pn and the lateral displacement at the ultimate load were larger for the same slenderness ratio.

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Effects of Slenderness ratio on Dynamic Behavior of Cantilever Beam Subjected to Follower Force (종동력을 받는 외팔보의 진동특성에 미치는 세장비의 영향)

  • Son, In-Soo;Yoon, Han-Ik;Ahn, Tae-Su
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.575-578
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    • 2008
  • In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

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Cross-section classification of elliptical hollow sections

  • Gardner, L.;Chan, T.M.
    • Steel and Composite Structures
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    • v.7 no.3
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    • pp.185-200
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    • 2007
  • Tubular construction is widely used in a range of civil and structural engineering applications. To date, the principal product range has comprised square, rectangular and circular hollow sections. However, hot-rolled structural steel elliptical hollow sections have been recently introduced and offer further choice to engineers and architects. Currently though, a lack of fundamental structural performance data and verified structural design guidance is inhibiting uptake. Of fundamental importance to structural metallic design is the concept of cross-section classification. This paper proposes slenderness parameters and a system of cross-section classification limits for elliptical hollow sections, developed on the basis of laboratory tests and numerical simulations. Four classes of cross-sections, namely Class 1 to 4 have been defined with limiting slenderness values. For the special case of elliptical hollow sections with an aspect ratio of unity, consistency with the slenderness limits for circular hollow sections in Eurocode 3 has been achieved. The proposed system of cross-section classification underpins the development of further design guidance for elliptical hollow sections.

Effects of Slenderness Ratio on Stability of Cracked Beams Subjected to Sub-tangential Follower Force (경사종동력을 받는 크랙 외팔보의 안정성에 미치는 세장비의 영향)

  • Gal, Young-Min;Ahn, Sung-Jin;Yoon, Han-Ik;Son, In-Soo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.961-966
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    • 2008
  • In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to Subtangential follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

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Effects of Slenderness Ratio on Dynamic Behavior of Cracked Beams Subjected to Subtangential Follower Force (경사종동력과 크랙을 가진 보의 진동특성에 미치는 세장비의 영향)

  • Son, In-Soo;Yoon, Han-Ik
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.9
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    • pp.112-120
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    • 2009
  • In this paper the purpose is to investigate the stability and variation of natural frequency of a cracked Timoshenko cantilever beams subjected to subtangential follower force. In addition, an analysis of the stability of a cantilever beam as the crack effect and slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force are derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. By using the results of this paper, we can obtain the judgment base that the choice of beam models for the effect of slenderness ratio and crack.

The Effect of Slenderness on the Design of Diagrid Structures

  • Mele, Elena;Imbimbo, Maura;Tomei, Valentina
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.83-94
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    • 2019
  • Diagrid structures have emerged in recent decades as an innovative solution for tube tall buildings, capable of merging structural efficiency and aesthetic quality. This paper investigates the effect of the building slenderness (grossly quantified by means of the aspect ratio, i.e., the ratio between the height and the plan dimension) on the structural behavior and on the optimal design parameters of diagrid tall buildings. For this purpose, building models with different slenderness values are designed by adopting preliminary design criteria, based on strength or stiffness demands; in addition, a design method based on a sizing optimization process that employs genetic algorithms is also proposed, with the aim to compare and/or refine the results obtained with simplified approaches.

Study on the Limit Slenderness of a Double Outrigger System (이중 아웃리거 구조 시스템의 한계 세장비에 대한 연구)

  • Yang, Jae-Kwang;Kang, Ho-Geun;Park, Sung-soo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.3
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    • pp.11-18
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    • 2018
  • Due to the recent overpopulation of urban cities, land shortage and soaring land prices have caused an increase in the demand for high-rise buildings. To build buildings on a limited land, the size of the building is important. Displacement control by horizontal loads in a skyscraper is critical to securing stability and usability of structures. Several systems have been proposed for efficient horizontal displacement control, and so far the study continues. Among them, the Outrigger System is a representative of the typical horizontal load resistance system. Although studies have been conducted so far to locate the optimal position of the outrigger, studies of the slenderness ratio of the buildings are still insufficient. Based on the Outrigger-Optimized Position equation, this study induces the calculation of the displacement of the outrigger installation building according to the slenderness ratio.

Determination of True Modulus of Elasticity and Modulus of Rigidity for Domestic Woods with Different Slenderness Ratios Using Nondestructive Tests (서로 다른 세장비에 대한 비파괴실험으로 국산재의 실질탄성계수와 전단탄성계수 결정)

  • Cha, Jae Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.1
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    • pp.36-42
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    • 2015
  • This study examined true modulus of elasticity (MOE) and modulus of rigidity (G) for domestic woods with different slenderness ratios (L/D) using the static bending and stress wave tests. Bending properties of small clear wood specimen of three domestic wood species were determined at 12% moisture content. The results of this study indicated that both MOR and MOE of domestic woods were affected by the slenderness ratio. As the slenderness ratio increased, MOR and MOE increased. G and true MOE of domestic timber beams were obtained at different slenderness ratios by flexure test and stress wave test. The values reported here can be useful if these species woods are used for structural purposes. However, the reported values are only indicative and do not represent the true average of wood species due to the limited number of specimens tested.