Equivalent slenderness ratio for built-up members

1993 ◽  
Vol 20 (4) ◽  
pp. 708-711 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada Elmahdy
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Load Carrying Capacity ◽  
Lateral Deformation ◽  
Numerical Example ◽  
Ratio Equation ◽  
Load Carrying ◽  
The One ◽  
Equivalent Slenderness Ratio

Built-up struts that buckle about an axis perpendicular to the plane of the connectors should be treated as a "built-up" member as opposed to a "simple" member. This mode of buckling causes shear and moments in the connectors which deform the connectors. These deformations increase the lateral deformation of the member and hence affect the load-carrying capacity. To account for this effect the easiest method is to use an equivalent slenderness ratio such as the one included in the Canadian Standard. This note outlines the derivation of the equivalent slenderness ratio equation, discusses when it should and should not be used, and includes a numerical example. A rewording of the applicable clause in the Canadian Standard is suggested. Key words: battens, built-up members, connectors, slenderness ratio.

scholarly journals Experimental Research on AFRP Reinforced Recycled Steel Tube Columns Subjected to Axial Compression

2017 ◽  
Vol 26 (6) ◽  
pp. 096369351702600
Author(s):  
Min Hou ◽  
Jiangfeng Dong ◽  
Lang Li ◽  
Shucheng Yuan ◽  
Qingyuan Wang
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Basalt Fiber ◽  
Steel Tube ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The One ◽  
Effective Use

In order to make an effective use of the recycled aggregate concrete (RAC), a total of six steel tube RAC columns and six basalt fiber (BF) reinforced RAC columns, including six columns that were externally strengthened with aramid fiber reinforced polymer (AFRP) sheets, were fabricated and tested. This were to provide a strengthening solution to upgrade the load carrying capacity, ductility and rigidity of the RAC filled steel tube columns. Besides, the recycled coarse aggregate (RCA) replacement ratios for production of RAC was analyzed. The results show that the load carrying capacity and ultimate displacements of the RAC filled ST columns could be improved greatly by adding of basalt fiber, especially for the specimens with 50% and 100% RCA replacement ratio. The similar result was also found for the specimens strengthened with AFRP reinforcement, along with the stiffness of the columns were enhanced obviously. Moreover, the highest improving on the load carrying capacity, stiffness and ultimate displacement was found in the specimens both reinforced by adding of BF and strengthening of AFRP. However, the failure modes of the specimens with BF reinforced RAC gave a higher deformability than the one with AFRP strengthening arrangement.

scholarly journals Starred angles supporting secondary trusses

1991 ◽  
Vol 18 (1) ◽  
pp. 118-129
Author(s):  
Murray C. Temple ◽  
Kenneth Hon-Wa Mok
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
The Other ◽  
Load Carrying Capacity ◽  
Industrial Buildings ◽  
Compression Members ◽  
Load Carrying ◽  
Structural Connections ◽  
Open Nature

In some large industrial buildings, it is common to span large areas by using primary trusses in one direction and secondary trusses in the other. The secondary trusses frame into the vertical web members in the primary trusses. Starred angles are frequently used as the vertical web members in the primary trusses because of their symmetrical cross section and the ease with which the connections can be made. These starred angles are usually designed as axially loaded members, but the open nature of the cross section and the fact that the secondary truss frames into one of the angles has raised some doubts about this loading assumption. As a result of this concern, an experimental research program was undertaken to investigate the behaviour and strength of starred angle web members supporting secondary trusses. The results obtained indicate that these starred angle compression members are not concentrically loaded, as the stress distribution across the angles is not uniform. It was found that if the slenderness ratio is modified in accordance with the requirements of ASCE Manual 52, the load-carrying capacity of the starred angles supporting secondary trusses can be determined using Clause 13.3.1 of CAN3-S16.1-M84. Key words: angles (starred), buckling, columns (structural), connections, trusses.

An Approximate Solution for the Infinitely Long, Gas Lubricated Slider Bearing

1965 ◽  
Vol 87 (4) ◽  
pp. 1085-1086
Author(s):  
H. J. Sneck
Keyword(s):  
Exact Solution ◽  
Approximate Solution ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Load Carrying ◽  
Numerical Design ◽  
The One ◽  
Design Calculations

The only exact solution for the infinitely long, gas-lubricated slider bearing is the one obtained by Harrison [1] for the plane wedge isothermal film. The resultant formulas for the pressure distribution and load-carrying capacity are complicated and therefore quite cumbersome in numerical design calculations. In the analysis to follow, a simplified, approximate solution is developed which can be applied to any infinitely long slider geometry.

scholarly journals 3D FE Analysis of an Embankment Construction on GRSC and Proposal of a Design Method

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yogendra K. Tandel ◽  
Chandresh H. Solanki ◽  
Atul K. Desai
Keyword(s):  
Carrying Capacity ◽  
Design Method ◽  
Soft Clay ◽  
Deformation Modulus ◽  
Diameter Ratio ◽  
Major Influence ◽  
Stone Column ◽  
Load Carrying Capacity ◽  
Lateral Deformation ◽  
Load Carrying

Stone column is often employed for strengthening of an embankment seated on deep soft clay. But in very soft clay having undrained shear strength less than or equal to 15 kPa, stone column may not derive adequate load carrying capacity and undergo large lateral deformation due to inadequate lateral confinement. In such circumstances, reinforcement to individual stone column by geosynthetics enhances load carrying capacity and reduces lateral deformation. This paper addresses parametric study on behaviour of embankment resting on Geosynthetic Reinforced Stone Column (GRSC) considering parameters such as stone column spacing to diameter ratio, deformation modulus of stone column material, geosynthetic stiffness, thickness of soft clay, and height of embankment by 3D numerical analysis. Finally, equation for Settlement Improvement Factor (SIF), defined as ratio between settlement of embankment without treatment and with geosynthetic reinforced stone column, is proposed that correlates with the major influence parameters such as stone column spacing to diameter ratio, deformation modulus of soft clay, and geosynthetic stiffness.

scholarly journals Balanced and unbalanced welds for angle compression members

1994 ◽  
Vol 21 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Murray C. Temple ◽  
Sherief S. S. Sakla
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Compressive Load ◽  
Tensile Load ◽  
Effective Length ◽  
Load Carrying Capacity ◽  
Compression Members ◽  
Load Carrying ◽  
Compressive Loads ◽  
Compressive Resistance

Angles used as web members in trusses are often welded to the chords with unbalanced welds. This is necessary because of space limitations. It is not known what effect such a weld has on the compressive load carrying capacity of an angle. The standards and specification examined allow an unbalanced weld for an angle. The justification for using such a weld is based on research conducted on angles in tension. For these members, it was concluded that an unbalanced weld does not affect the tensile load carrying capacity of the angle. Research results for angles with different weld patterns subjected to compressive loads are not available in the literature. Eighteen tests were conducted on angle compression members with various weld patterns. It was determined that an unbalanced weld is detrimental to the load carrying capacity of an intermediate length angle but is beneficial for a slender angle. Key words: angles, column (structural), compressive resistance, effective length, standards, welds.

Finite Element Analysis of Ultimate Load-Carrying Capacity of CFST-CSW Arches

2010 ◽  
Vol 163-167 ◽  
pp. 1910-1915
Author(s):  
Jing Gao ◽  
Bao Chun Chen
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Parametric Study ◽  
Slenderness Ratio ◽  
Limit State ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Load Carrying ◽  
Modeling Techniques ◽  
Ultimate Load Carrying Capacity

In order to better understand the behavior of CFST-CSW arch, experiment on two hingeless CFST-CSW arches are described in this paper, subjected to in-plane symmetrical and asymmetrical loading respectively. The experiment yield important information regarding the manifestation of the limit state and also afford an opportunity to verify finite element modeling techniques for use in a parametric study. The parametric study reveals that the load-carrying capacity is influenced by many factors including the rise-to-span ratio, slenderness ratio, loading cases and material properties.

Interconnection of widely spaced angles

1988 ◽  
Vol 15 (4) ◽  
pp. 732-741 ◽  
Author(s):  
Murray C. Temple ◽  
Joo Chai Tan
Keyword(s):  
Key Words ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Structural Design ◽  
Failure Load ◽  
Building Codes ◽  
Load Carrying Capacity ◽  
Insignificant Effect ◽  
Load Carrying ◽  
Theoretical Results

Research on the interconnection of widely spaced back-to-back angles has not been conducted. This research was carried out with the aim of developing rules for the design and spacing of interconnectors in such members. Four parameters—the number of interconnectors, the back-to-back spacing between angles, the weld pattern used to connect the interconnectors to the angles, and the thickness of the interconnectors—were studied. The experimental and the theoretical results for the slender double angles confirm that only one interconnector, of practical proportions, is required to make the widely spaced angles act as an integral unit. Both the separation between angles, within reason, and the weld pattern used to connect the interconnectors to the angles had an insignificant effect on the failure load and the failure mode. The thickness of the interconnector did affect the load-carrying capacity of the strut, but only when the thickness of the interconnector was impractically small. The forces and moments in the interconnectors are very small. Key words: angles, back-to-back, buckling, building (codes), columns (structural), design interconnection.

scholarly journals Experimental Behaviour of Steel Tubular Columns for Varying in Filled Concrete

2017 ◽  
Vol 63 (4) ◽  
pp. 149-160 ◽  
Author(s):  
P. Sangeetha ◽  
R. Senthil
Keyword(s):  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Concrete Core ◽  
Composite Action ◽  
Tubular Columns ◽  
Load Carrying ◽  
Cfst Columns ◽  
Quarry Dust

AbstractThis paper investigates the behaviour of axially-loaded tubular columns filled with M20 grade concrete and partially replaced concrete. The parameters varying in the study are slenderness ratio (13.27, 16.58 & 19.9), and normal M20 grade concrete, partially replaced quarry dust and concrete debris. The effects of the various concrete mixes and composite action between the steel tube and the concrete core are studied and a graph visualizing the differences between the load carrying capacity and the axial deflection is plotted. Some of the performance indices like the Ductility Index (DI), Concrete Contribution Ratio (CCR), Confinement Index (θ) and Strength Index (SI) are also evaluated and compared amongst the CFST columns. From the results it has been noted that an increase in the L/D ratio decrease the behaviour of the composite columns irrespective of the in filled materials. The composite action was achieved in the CFST columns filled with partially replaced quarry dust and concrete debris when compared with hollow steel columns. The load carrying capacity of the CFST column increases by 32 % compared with the hollow tubular columns.

Local effective length factor in the equivalent slenderness ratio

1995 ◽  
Vol 22 (6) ◽  
pp. 1164-1170 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada Elmahdy
Keyword(s):  
Key Words ◽  
Slenderness Ratio ◽  
Effective Length ◽  
Component Part ◽  
Square Root ◽  
Ratio Equation ◽  
Effective Length Factor ◽  
Equivalent Slenderness Ratio ◽  
Compressive Resistance

The Canadian Standard S16.1 specifies an equivalent slenderness ratio to be used when determining the compressive resistance of a built-up member when buckling occurs about an axis perpendicular to the interconnectors. This equivalent slenderness ratio is the square root of the sum of the squares of the slenderness ratio of the built-up member acting as a unit and the maximum slenderness ratio of a component part between fasteners. The Standard specifies for this second component that an effective length factor be used, the magnitude of which depends on the type of connection. An effective length factor of 0.65 is specified when welds are used. This is of concern to the authors. It is pointed out that the derivation of this equation by Bleich, and by Timoshenko and Gere, does not contain an effective length factor in the second term. The effective length factor of 0.65 comes from a paper by Duan and Chen. Results of tests on five built-up members, channels arranged in the toe-to-toe configuration, indicate that the use of an effective length factor of 0.65 gives unconservative results, especially when the member is slender. It is recommended that a factor of 1.0 be used in the second term of the equivalent slenderness ratio equation. Key words: battens, built-up members, equivalent slenderness ratio, interconnectors, standards.

Numerical Method and Experimental Study on the Ultimate Load Carrying Capacity of Four Tube CFST Latticed Columns

2010 ◽  
Vol 163-167 ◽  
pp. 2224-2233
Author(s):  
Li Zhong Jiang ◽  
Wang Bao Zhou ◽  
Jing Jing Qi
Keyword(s):  
Numerical Method ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Confinement Effect ◽  
Load Carrying Capacity ◽  
Short Columns ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

The paper presents a numerical method for calculating the load-deformation response and ultimate load carrying capacity of Concrete Filled Steel Tubular (CFST) latticed columns A half-wave sinusoidal function is assumed for the deflected shape of the column. The effect of confinement and shear deformation are included in the analysis, and the corresponding equilibrium equation is established. The method applies to eccentrically loaded compression members bent in single curvature. Unequal end eccentricities can be considered. Test results are reported for seventeen four latticed column specimens with varying end eccentricities and slenderness ratios. The obtained results show that eccentricity has significant effect on the bearing capacity of specimen, and the slenderness ratio also has some influence. The diagonal lacing bars remained in the elastic state during the entire load range. When specimens go into the nonlinear stage, Poisson's ratio of the near-load steel tube increases and a significant confinement effect can be observed. For the far-load steel tube, confinement effect does not occur to a significant extent. Specimen failure is due to overall instability except in the case of several individual short columns. Good agreement was found between the theoretical and experimental results using the numerical method developed in the paper. The proposed numerical method is shown to be more accurate than the current method presented in the Chinese code.

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