Linear buckling analysis of perforated plates subjected to localised symmetrical load

Holes are often unavoidable in webs of steel beams and in plates, due to inspection, maintenance and also aesthetic purposes. In these situations, the presence of holes may cause redistribution of plane stresses in plates with a significant reduction of stability. In this paper, linear buckling analyses of perforated plates subjected to localised symmetrical load, with circular and rectangular holes, are developed. The results show some relevant differences between the behaviour of the plate subjected to localised symmetrical load with respect to that of uniform compressive load, already known in literature, with a significant increase in the elastic critical load value. The buckling coefficient of square and rectangular perforated panels under symmetrical uniform compression assumes the same value of corresponding whole panels, and it strongly increases for localised symmetrical load, reducing its increment on the basis of the diameter of the hole. Lastly, some indications are given on the best orientation of rectangular holes when localised load are applied showing differences with the uniform compression load case. Holes with the longest edge parallel to the transverse direction of the panel subjected to uniform compression loads are preferable for stability purposes. According to present results obtained for localised loads, holes with the longest edge along the longitudinal direction are preferable.