Modification for French Rules Equations for Effective Length Factors of Steel Compression Members

2016 ◽  
Vol 11 (5) ◽  
pp. 5-17
Author(s):  
Magdy I. Salama ◽  
Saeed Mazroa
Keyword(s):  
Effective Length ◽  
Compression Members

Flexural-Torsional Buckling of Double-Angle Compression Members

2013 ◽  
Vol 284-287 ◽  
pp. 1334-1339
Author(s):  
Jui Ling Liu ◽  
Dung M. Lue ◽  
Ching H. Lin
Keyword(s):  
Computer Program ◽  
Effective Length ◽  
Torsional Buckling ◽  
Easy Task ◽  
Routine Design ◽  
Compression Members ◽  
The Difference ◽  
Flexural Torsional Buckling ◽  
Torsion Condition

The evaluation for double-angle compression members is a tedious procedure and is not an easy task for practicing engineers. In this study, a computer program has been developed to calculate the Pu based on the AISC specifications. It is found that the calculated value is quite close to the tabulated one if effective length (KL) is longer than 10 feet. However, the Pu is not tabulated for effective length less than 10 feet in some lager sections. It is found that the differences between the calculated value and the interpolated value could be as much as 20%. Unfortunately, the difference errors are not on conservative side and the use of interpolated values is not acceptable in practice. This study evaluates all double-angle compressive formulas provided by the AISC manuals and the comparisons among them are presented. The Pu versus KL curves, in which effective lengths less than 10 feet are added and plotted. Some supplementary tabulated values, which required in routine design and not listed in current AISC design manuals, are also furnished. This study will fulfill the needs for those who seek higher performance and wider coverage when evaluating the design of double-angle compression members under flexural-torsion condition.

Influence of the assumed effective length factor on the load carrying capacity of steel angles in compression

1995 ◽  
Vol 22 (6) ◽  
pp. 1171-1177
Author(s):  
Murray C. Temple ◽  
Davide M. Petretta ◽  
Catherine Morand
Keyword(s):  
Principal Axis ◽  
Design Procedure ◽  
Effective Length ◽  
Experimental Program ◽  
Load Carrying Capacity ◽  
Effective Length Factor ◽  
Compression Members ◽  
Load Carrying ◽  
Steel Angles ◽  
Compressive Resistance

Single angle compression members are usually attached by one leg only. In Canada it is common practice when designing such members to neglect the end eccentricities, to assume the angle buckles about the minor principal axis, and to assume an effective length factor of 1.0. Clause 13.3.1 of S16.1 is then used to calculate the compressive resistance. An experimental program was undertaken to determine the effect that the assumed effective length factor has on the compressive resistance of such angles. Eighteen specimens were tested in which the angles were slender or of intermediate length. The effective length factor was assumed to be 1.0, 0.9, or 0.5. It was determined that when there is substantial restraint at the ends of the angles the assumed effective length factor has a very significant effect on the compressive resistance of an angle attached by one leg. Key words: angles, axis of bending, buckling, design procedure, effective length factor.

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.

On the Effective Length of Compression Members in Double-Layer Grids

1991 ◽  
Vol 6 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Usama R. Madi ◽  
Adel A. El-Tayem
Keyword(s):  
Double Layer ◽  
Effective Length ◽  
Compression Members

scholarly journals End Restraints in Steel Angles in Lattice Towers

2017 ◽  
Vol 11 (1) ◽  
pp. 738-747
Author(s):  
Sriram Kalaga
Keyword(s):  
Test Data ◽  
Effective Length ◽  
Compression Members ◽  
Adjustment Factors ◽  
Lattice Tower ◽  
Steel Angles ◽  
Lattice Towers ◽  
Connection Length

Introduction: Test data on single angle compression members with various end connection arrangements is used to develop adjustment factors for effective buckling lengths. A connection length parameter is proposed and evaluated based on test data. Results from a total of 31 equal leg test angles with single-, double- bolts and fixed ends are used. Methods: Slenderness ratios considered ranged from 150 to 312. Angle sizes ranged from 38 x 38 x 3.2 (mm) to 89 x 89 x 6.4 (mm). Estimated connection lengths were about 12.5% of the member length for single-bolt joints; 24.7% for double-bolt joints and 45.6% for fixed joints. Computed effective length factors ranged from 0.544 to 0.875. Results: Results seem to indicate that it is possible to define and calculate connection length of a lattice tower angle member. Suggestions for incorporating connection length issues in routine designs are made.

Experimental study of the buckling strength of compression members connected to coplanar tension members

1989 ◽  
Vol 16 (3) ◽  
pp. 249-257 ◽  
Author(s):  
André Picard ◽  
Denis Beaulieu
Keyword(s):  
Experimental Study ◽  
Plane Deformation ◽  
Effective Length ◽  
Small Scale ◽  
Transverse Stiffness ◽  
Effective Length Factor ◽  
Tension Member ◽  
Compression Members ◽  
Out Of Plane ◽  
Tension Members

In structural systems using cross braces, the compression members are restrained against out-of-plane buckling by the tension members. It was shown in a theoretical study that the transverse stiffness provided by a tension member depends on the tension force in the member and on the flexural stiffness against out-of-plane deformation of the tension member. Equations were derived to determine the effective length factor of the compression member, taking into account the transverse stiffness of the tension member.This paper presents the results of a small-scale experimental study, which shows that the proposed equations slightly underestimate the transverse stiffness and overestimate the effective length factor. These equations are therefore conservative, but they indicate that an effective length factor much smaller than 1.0 can be used. Key words: stability, elastic buckling, elastic supports, cross braces.

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