Analytical effective width equations for limit state design of thin plates under non-homogeneous in-plane loading

Abstract

The effective width concept has been widely used in engineering practice for the computation of ultimate strength of slender members. Many design codes employ this concept in order to compensate for the stiffness reduction in the post-buckling state. Extensive work was done to develop effective width equations for plates under uniform compression, while little attention has been given for plates under non-homogeneous in-plane loading. North American, British and European design codes provide only expressions for the computation of the elastic buckling loads for plates under this load combination, while the effective width calculation is based on the uniformly compressed plates. It will be shown that due to the non-uniformity of the applied load, the stress characteristics in the post-buckling state are different from the uniform compression case, thus requiring special treatments. The paper presents analytical closed form expressions for the computation of effective width of thin plates under non-homogeneous in-plane loading. The longitudinal edges are assumed to be straight and free to translate in the plane of the plate. The proposed expressions are very useful for limit state design of slender I-sections of beam columns or channel sections under this general type of loading. They enable the designers to compute the effective width of the section with the aid of simple formulas that, for design purposes, are suitable for hand-calculation and avoid the cost and effort that any numerical non-linear analysis may require.

Design of Columns in Terms of Stability

“…The μ and ψ parameters are non-dimensionless coefficients that define the elasticity of the connection at point M of the column and their value depends on the type and the dimensions of the cross section, i.e. the effective width b eff [13]. The dependence of the normalized force p N according to parameters μ and ψ is illustrated in Fig.…”

Economical design procedures for built-up box sections subject to compression and bi-axial bending

“…Bedair [13,14] is largely affected by the restraints imposed by the webs. Other investigations by Bedair [15][16][17][18][19][20][21][22] highlighted the behaviour of W and channel steel sections under various loading combinations.…”

Local stability of partially restrained rectangular tubes subject to shear, compression, and bending

“…Reyes and Guzmán 10 conducted experiments of box sections composed of two welded C‐sections subject to axial loading. Bedair 11–19 highlighted behavior of box sections subject to uniform compression with applications to bridge and industrial facilities. Cost effective design strategies and engineering guidelines were presented to optimize the design and fabrication costs.…”

“…Empirical studies were also performed for local buckling strength of steel tubes filled with concrete by Sakai et al 22 and Wright 23 . Comprehensive reviews for various numerical, analytical, and experimental investigations were presented by Bedair 16,18,19 …”