• Title, Summary, Keyword: Slenderness ratio

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Slenderness ratio of telescopic cylinder-columns

  • Sugiyama, Yoshihiko;Ohtomo, Takamitsu
    • Structural Engineering and Mechanics
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    • v.12 no.3
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    • pp.329-339
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    • 2001
  • The present paper deals with the effective slenderness ratio of telescopic cylinders as a long column having different cross sections. Firstly, the slenderness ratio defined in the current standard for the telescopic cylinders is discussed to point out some difficulties which arise when the ratio is applied to the column having different cross sections. Secondly, a new effective slenderness ratio is proposed for columns having different cross sections by introducing a partial effective slenderness ratio. Finally, the proposed slenderness ratio is applied, for extending and development of discussion, to a two-staged column having piece-wise constant cross sections and a cylindrical column having linearly varying diameters.

A Study on the Change in Hole Precision with Slenderness Ratio of Boring Cutter (보링커터의 세장비에 따른 구멍 정밀도 변화에 관한 연구)

  • Chun, Se-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.7-12
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    • 2017
  • It is assumed that the buckling and cutting conditions depending on the slenderness ratio will affect the machining quality of the rotary boring tool mounted on a milling machine. In this study, the boring cutter was designed and fabricated to precisely create the Ø30 hole. Through the performance evaluation, the accuracy of the hole according to the slenderness ratio and cutting conditions was analyzed, and the following conclusions were obtained. The higher the RPM, the smaller the change in the working diameter, and the smaller the hole. Next, the smaller the slenderness ratio, the smaller the change in straightness due to the change in cutting conditions. Finally, the slenderness ratio also affects the tendency for changes in the concentricity. The larger the slenderness ratio, the more sensitive the concentricity to changes in cutting conditions.

Mechanical behavior of Beishan granite samples with different slenderness ratios at high temperature

  • Zhang, Qiang;Li, Yanjing;Min, Ming;Jiang, Binsong
    • Geomechanics and Engineering
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    • v.24 no.2
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    • pp.157-166
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    • 2021
  • This paper aims at the temperature and slenderness ratio effects on physical and mechanical properties of Beishan granite. A series of uniaxial compression tests with various slenderness ratios and temperatures were carried out, and the acoustic emission signal was also collected. As the temperature increases, the fracture aperture of intercrystalline cracks gradually increases, and obvious transcrystalline cracks occurs when T > 600℃. The failure patterns change from tensile failure mode to ductile failure mode with the increasing temperature. The elastic modulus decreases with the temperature and increases with slenderness ratio, then tends to be a constant value when T = 1000℃. However, the peak strain has the opposite evolution as the elastic modulus under the effects of temperature and slenderness ratio. The uniaxial compression strength (UCS) changes a little for the low-temperature specimens of T < 400℃, but a significant decrease happens when T = 400℃ and 800℃ due to phase transitions of mineral. The evolution denotes that the critical brittle-ductile transition temperature increases with slenderness ratio, and the critical slenderness ratio corresponding to the characteristic mechanical behavior tends to be smaller with the increasing temperature. Additionally, the AE quantity also increases with temperature in an exponential function.

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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    • 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 plate slenderness on the ultimate strength behaviour of foam supported steel plate elements

  • Pokharel, Narayan;Mahendran, Mahen
    • Structural Engineering and Mechanics
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    • v.21 no.4
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    • pp.407-422
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    • 2005
  • Plate elements in fully profiled sandwich panels are generally subjected to local buckling failure modes and this behaviour is treated in design by using the conventional effective width method for plates with a width to thickness (b/t) ratio less than 100. If the plate elements are very slender (b/t > 1000), the panel failure is governed by wrinkling instead of local buckling and the strength is determined by the flexural wrinkling formula. The plate elements in fully profiled sandwich panels do not fail by wrinkling as their b/t ratio is generally in the range of 100 to 600. For this plate slenderness region, it was found that the current effective width formula overestimates the strength of the fully profiled sandwich panels whereas the wrinkling formula underestimates it. Hence a new effective width design equation has been developed for practical plate slenderness values. However, no guidelines exist to identify the plate slenderness (b/t) limits defining the local buckling, wrinkling and the intermediate regions so that appropriate design rules can be used based on plate slenderness ratios. A research study was therefore conducted using experimental and numerical studies to investigate the effect of plate slenderness ratio on the ultimate strength behaviour of foam supported steel plate elements. This paper presents the details of the study and the results.

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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    • 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 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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    • 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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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.

Parametric study on eccentrically-loaded partially encased composite columns under major axis bending

  • Begum, Mahbuba;Driver, Robert G.;Elwi, Alaa E.
    • Steel and Composite Structures
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    • v.19 no.5
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    • pp.1299-1319
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    • 2015
  • This paper presents a detailed parametric study, conducted using finite element tools to cover a range of several geometric and material parameters, on the behaviour of thin-walled partially encased composite (PEC) columns. The PEC columns studied herein are composed of thin-walled built-up H-shaped steel sections with concrete infill cast between the flanges. Transverse links are provided between the opposing flanges to improve resistance to local buckling. The parametric study is confined to eccentrically-loaded columns subjected to major axis bending only. The parameters that were varied include the overall column slenderness ratio (L/d), load eccentricity ratio (e/d), link spacing-to-depth ratio (s/d), flange plate slenderness ratio (b/t) and concrete compressive strength ($f_{cu}$). The overall column slenderness ratio was chosen to be the primary variable with values of 5, 10 and 15. Other parameters were varied within each case of L/d ratio. The effects of the selected parameters on the behaviour of PEC columns were studied with respect to the failure mode, peak axial load, axial load versus average axial strain response, axial load versus lateral displacement response, moment versus lateral displacement behaviour and the axial load-moment interaction diagram. The results of the parametric study are presented in the paper and the influences of each of the parameters investigated are discussed.

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.