The Influence of Small Strenghtenings and Weakenings on Load Carrying Capicity of Plates

Lower quality plates are often manufactured by cutting or stamping sheet metal produced by cold rolling and delivered in rolls. This sheet metal cannot be ideally straightened and its thickenss is often not equal to the nominal thickness. Due to the manufacturing technology and the straightening process, places of unequal thickness can be observed in the direction of rolling, i.e. at right angle to the edge of the roll. The load carrying capacity of a square plate depends on the angle at which it is cut out from such a sheel metal plate or on the direction of strengthening or weakening with respect to the loaded edge. The paper gives an estimation of the influence of small strengthenings and weakenings on the stability of a square plate. Strengthenings and weakenings were studied with respect to the angle they form with the loaded edge. It was found that small strengthenings and weekenings forming a right angle with the loaded edge do not affect its stability. However, strengthenings and weakenings forming any other angle with the loaded edge may importantly lower the buckling stability of the plate.