Influence of cropping on effective-length factors of tubular steel struts

1979 ◽  
Vol 6 (2) ◽  
pp. 260-267 ◽  
Author(s):  
G. Morris
Keyword(s):  
Experimental Investigation ◽  
Effective Length ◽  
Elastic Buckling ◽  
Buckling Loads ◽  
Fabrication Procedure

An experimental investigation is made of the influence of cropping, a relatively new fabrication procedure, on effective-length factors for round tubular steel struts. Tests of 18 companion pairs of cropped and sawn strut specimens, with end plates providing various degrees of end-fixity, are described. The Southwell plot method, using both transverse displacements and strains, is used to determine elastic buckling loads. These are in turn used to compute effective-length factors. Those for the sawn specimens approach 1.0 for very small end-fixity and 0.5 for large end-fixity. Except for the specimens with very small end-fixity, the effective-length factors for the cropped specimens are approximately 15% larger than those for the corresponding sawn specimens.

scholarly journals Investigation of natural frequencies of axially loaded thin-walled columns

2018 ◽  
Vol 219 ◽  
pp. 02018
Author(s):  
Łukasz Żmuda-Trzebiatowski
Keyword(s):  
Applied Load ◽  
Natural Frequencies ◽  
Elastic Buckling ◽  
Correlation Technique ◽  
Buckling Loads ◽  
Perfectly Plastic ◽  
Linear Buckling ◽  
Thin Walled ◽  
Elastic Perfectly Plastic ◽  
Flexural Torsional Buckling

The paper deals with correlation between natural frequencies of two steel thin-walled columns and the corresponding applied load. The structures are made of cold-formed lipped channel sections. The columns lengths were assumed to follow two buckling patterns – global flexural and flexural-torsional buckling. In the thicker structure two material models were considered – linearly-elastic and elastic-perfectly plastic. Numerical computations cover dynamic eigenvalue problem, linear buckling and geometrically (and materially) non-linear analysis. The correlation between squares of natural frequencies and the applied load is linear in both columns. The first natural frequencies drop to zero due to structural buckling. This method, called the Vibration Correlation Technique, allows to predict buckling loads on the basis of measured vibration frequencies of the structures. Plasticity does not affect the corresponding curves – the use of the presented technique is limited to the structures exhibiting elastic buckling behaviour.

Preliminary Study on Application of Metal Members with Corrugated Webs in the Supports of Soft Rock

2011 ◽  
Vol 90-93 ◽  
pp. 2380-2388 ◽  
Author(s):  
Li Li Wu ◽  
Zhen Yu ◽  
Dong Dong Zhang
Keyword(s):  
Soft Rock ◽  
Steel Plates ◽  
Elastic Buckling ◽  
Buckling Loads ◽  
Corrugated Webs ◽  
New Type ◽  
Mechanical Performances ◽  
Sectional Parameters ◽  
Rock Tunnels ◽  
Rock Tunnel

A new type of metal support named H-Shaped members with corrugated webs is put forward for the soft rock tunnels or roadways supports. The H-shaped member with corrugated webs is welded by corrugated webs and plain flange steel plates. The loading behaviors of the members are greatly improved by the corrugation in the webs compared with that of the members with plain webs. The new type of support has fair good mechanical performances with its own merits, including easy fabrication, fast construction etc. especially it can adapt to the large deformation of soft rocks. The elastic buckling behaviors are analyzed for the new horse-shoe shape supports with corrugated webs. The influences of the sectional parameters on the elastic buckling loads are discussed herein. Results show that the wave amplitude and wave height of corrugated webs have less influence on the buckling loads than those of the height of the webs and the width of the flanges etc. Some problems worth studying in the future for the new type of tunnel supports are also raised. Keywords: corrugated web; support structure; soft rock; tunnel; buckling

scholarly journals Analysisof Effective Length Factors of Hinged Pitched-Roof Framed Column with Sway under Arch Effect

2020 ◽  
Vol 165 ◽  
pp. 04069
Author(s):  
Ping Li ◽  
Liping Liu ◽  
Zunli Teng
Keyword(s):  
Order Effect ◽  
Effective Length ◽  
Elastic Buckling ◽  
Uniform Load ◽  
Calculated Length ◽  
Arching Effect ◽  
Arch Effect ◽  
Rigid Frame ◽  
Standards And Regulations ◽  
Inclined Beam

Aiming at the limitation of the calculated length coefficient of the gable portal rigid frame columns in the standards and regulations, which ignores the influence of the arch effect caused by the axial force of the inclined beams lope, this paper uses the elastic buckling equation of the solid-webbed articulated pitched-roof frame, considered 𝑃−𝛥 second-order effect and the arch effect of the inclined beam under uniform load together. And the length coefficient calculated is analyzed. It is concluded that the larger the slope of the inclined beam and the ratio of the rigid frame span are, the more obvious the arching effect is, and the larger the calculated length coefficient of the rigid frame column is.

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