Shear buckling of plates and thin-walled channel sections with holes

Abstract

Thin-walled structural channel members are commonly manufactured with cut-outs to allow access for building services such as plumbing, electrical and heating systems in the walls and ceilings. The presence of holes in the members will cause changes in the stress distribution and there will be consequently changes in the buckling characteristic and ultimate strength capacity. Recent work by Pham and Hancock has provided solutions to determine the shear buckling load using the Spline Finite Strip Method (SFSM) for whole thin-walled channel sections without holes. In this paper, the same methodology is utilised to study and provide solutions to the elastic shear buckling firstly for the perforated square plates and subsequently for the whole thin-walled lipped channel sections with centrally located holes. Both circular and square holes with the same sizes and diameters were chosen for investigation. The main variables are the diameters of the circular holes and the sizes of the square holes. While there is only uniform pure shear applied throughout in square plates, three different cases for shear loading in the channel are considered to maintain longitudinal equilibrium. The method is also benchmarked against the Finite Element Method (FEM) using software package ABAQUS/Standard in all cases. Comparisons between hole shapes, loading cases and buckling modes of both square plates and channels are included. For design purposes, approximate equations for shear buckling coefficients of square plate and channel section containing central circular and square holes are also proposed in this paper. Design example is also provided for design purposes.