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http://dx.doi.org/10.12989/sem.2007.26.6.673

On the use of the Lagrange Multiplier Technique for the unilateral local buckling of point-restrained plates, with application to side-plated concrete beams in structural retrofit  

Hedayati, P. (Department of Civil Engineering, Isfahan University of Technology)
Azhari, M. (Department of Civil Engineering, Isfahan University of Technology)
Shahidi, A.R. (Department of Civil Engineering, Isfahan University of Technology)
Bradford, M.A. (Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales)
Publication Information
Structural Engineering and Mechanics / v.26, no.6, 2007 , pp. 673-685 More about this Journal
Abstract
Reinforced concrete beams can be strengthened in a structural retrofit process by attaching steel plates to their sides by bolting. Whilst bolting produces a confident degree of shear connection under conditions of either static or seismic overload, the plates are susceptible to local buckling. The aim of this paper is to investigate the local buckling of unilaterally-restrained plates with point supports in a generic fashion, but with particular emphasis on the provision of the restraints by bolts, and on the geometric configuration of these bolts on the buckling loads. A numerical procedure, which is based on the Rayleigh-Ritz method in conjunction with the technique of Lagrange multipliers, is developed to study the unilateral local buckling of rectangular plates bolted to the concrete with various arrangements of the pattern of bolting. A sufficient number of separable polynomials are used to define the flexural buckling displacements, while the restraint condition is modelled as a tensionless foundation using a penalty function approach to this form of mathematical contact problem. The additional constraint provided by the bolts is also modelled using Lagrange multipliers, providing an efficacious method of numerical analysis. Local buckling coefficients are determined for a range of bolting configurations, and these are compared with those developed elsewhere with simplifying assumptions. The interaction of the actions in bolted plates during buckling is also considered.
Keywords
bolting; contact problem; lagrange multipliers; local buckling; side-plates; unilateral;
Citations & Related Records

Times Cited By Web Of Science : 3  (Related Records In Web of Science)
Times Cited By SCOPUS : 3
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