Effect of the Elastic Restraint by Adjacent Plate Component on the Local Buckling of Orthotropic Box-Shape Flexural Members

This paper presents a parametric study on compound cold-formed steel sections as flexural members. The compound members are used to sustain higher load and solve the problems of local buckling and lateral torsional buckling. The aim of this study is to investigate the strength of compound cold-formed steel section subjected to pure bending. Moment capacity of the compound section is calculated in accordance to Eurocode 3. The compound cold-formed steel sections proposed in this study are made up of two cold-formed steel C-section and hot-rolled plates. Steel plates with thickness of 3 mm to 8 mm are added to the cold-formed double C-section with the purpose to increase the bending capacity. From the comparison, moment capacity of compound sections give higher value as compared to cold-formed steel C-section with the comparison ratios range between 1.15 and 3.30. Results from the study show that compound cold-formed steel sections able to enhance the strength in resisting pure bending by adding steel plate at the flanges and web of the section. On the other hand, finite element modeling using ANSYS is carried out on two of the selected compound cold-formed steel sections and the results show good agreement with analytical results.

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Elastic Buckling Strength of Restrained Orthotropic Web Plates

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.261-263.615 ◽

2004 ◽

Vol 261-263 ◽

pp. 615-620

Author(s):

Jae Ho Jung ◽

Soon Jong Yoon ◽

S.K. You

Keyword(s):

Local Buckling ◽

Solution Technique ◽

Power Series Solution ◽

Flexural Members ◽

Buckling Strength ◽

Longitudinal Edge ◽

Flexural Member ◽

Degree Of Restraint ◽

Elastically Restrained ◽

Web Plates

In this paper, the buckling behavior of elastically restrained orthotropic web plates is investigated. In general, the pultruded FRP structural member is composed of flat plate elements and each plate element is elastically restrained against rotation by adjacent plate components. For finding the local buckling strength of composite flexural member considering the elastic restraint at the juncture of plate components, the orthotropic web plate is modeled as an elastically restrained orthotropic plate under linearly distributed in-plane forces. For the derivation of buckling equation, the power series solution technique is employed. For the plate having different mechanical properties, the parametric studies are conducted by varying the degree of restraint along the longitudinal edge under compression. By using the results obtained, simplified form of equation is also developed so that the practicing engineers can evaluate the buckling stress of such a plate for the preliminary design of FRP flexural members.

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Effect of the Elastic Restraint by Adjacent Plate Component on the Local Buckling of Orthotropic Box-Shape Flexural Members

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.297-300.1253 ◽

2005 ◽

Vol 297-300 ◽

pp. 1253-1258

Author(s):

Jae Ho Jung ◽

Soon Jong Yoon ◽

Sung Kun You ◽

Seok Goo Youn

Keyword(s):

Analytical Procedure ◽

Local Buckling ◽

Closed Form Solution ◽

Form Solution ◽

Buckling Analysis ◽

Factors Affecting ◽

Flexural Members ◽

Theoretical Predictions ◽

Flexural Member ◽

Elastically Restrained

The local buckling analysis of thin walled member is generally conducted by modeling each plate component as an isolated plate with elastically restrained boundaries. When this analytical model is used for the orthotropic flexural members, it is necessary to obtain the degree of elastic restraint provided by adjacent plate. In this study, the equation to find the coefficient of elastic restraint by adjacent plate components of an orthotropic box-shape flexural member was derived by employing the energy approach, and the factors affecting the elastic restraint were briefly discussed. Using the suggested equation, the coefficient of elastic restraint was calculated, and the local buckling analysis was conducted according to the stepwise analytical procedure published by the authors. The theoretical predictions were in good agreement with results obtained by the closed-form solution. The local buckling strength of an orthotropic box-shape flexural member can be easily obtained through stepwise analytical procedure with the proposed equation that accounts for the effect of elastic restraint imposed by adjacent plate components.

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Flexural Tests on the H-Section Simple Beams with Local Buckling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.1677 ◽

2011 ◽

Vol 105-107 ◽

pp. 1677-1680

Author(s):

Young Bong Kwon ◽

Jin Hwan Cheung ◽

Byung Seung Kong ◽

Hwan Woo Lee ◽

Kwang Kyu Choi

Keyword(s):

Local Buckling ◽

Bending Moment ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Moment Capacity ◽

Flexural Members ◽

Negative Effect ◽

Large Width ◽

The Moment ◽

Flexural Tests

This paper describes a series of flexural tests conducted on the H-section beams fabricated from SM490 plate of thickness 0.6mm with nominal yield stress 315 MPa. Flexural members with large width-to-thickness ratios in the flanges or the web may undergo local buckling before lateral-torsional buckling. The local buckling has a negative effect on the moment capacity based on the lateral-torsional buckling. Simple bending moment capacity formulas for flexural members were calibrated to the test results to account for interaction between local buckling and lateral-torsional buckling. The ultimate flexural strengths predicted by the proposed formulas for direct strength method were compared with the AISC (2005) and Eurocode3 (2003). The comparison showed that the moment formulas proposed can predict conservatively the bending moment capacity of H-section flexural members with local buckling.

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