Publication: Behaviour of cold-formed steel built-up colums (I-Section) under axial compression
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Date
2015
Authors
Nur Amalina Anuar
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Abstract
This Bachelor Degree/project explains a series of axially-compressed tests executed on cold-formed-steel built-up I columns composed of two lipped C-section fabricated back-to-back from high tensile steel plates with nominal yield stress of 550 MPa. This series of parametric studies were carried out by varying the thickness and web depth of Lysaght C-sections from C7560, C7575, C7510 and C10010 over a range of lengths of 300 mm to 700 mm such that column curves could be obtained. Each span denotes different slenderness ratios, & values (L/radius of gyration) ranging from 12.2 to 37.2 and different width-to-thickness ratio ranging from 75 mm to 125 mm. The objectives of this project were to study the buckling failure modes of cold formed steel column channels and to determine the ultimate compression capacity of the I-section with different section properties when subjected to axial compression. The test strengths were compared with the design strengths based on North American Specification (AISI-2007) for the design of cold-formed steel structural members. Vertical and horizontal deflections were measured using 4 LVDT (Linear Variable Displacement Transducer) to precisely examine the buckling modes of failure and analyse the load-displacement relationship. All of these columns failed by local and distortional buckling as well as Euler buckling for long columns. The effect of width- to-thickness ratio increases as the local buckling and distortional buckling capacity decrease. For distortional buckling mode of failure, few parameters play an important role for a cold formed steel to fail under this mode. Among the parameters are flange length, length of lipped channel and web depth. Other buckling modes such as flexural and flexural-torsional buckling were also observed. The results provide useful information regarding allowable load estimation of cold-formed steel column channels. The details of these investigations and the outcomes are presented in this thesis.
Description
TA684.N87 2015
Keywords
Steel , Buckling