Ultimate strength of square plates subjected to compression (1st Report)

Abstract

When structures are constructed by welding, structural elements are always accompanied by welding residual stresses and usually also by deformation. Therefore, when the rigidity and strength of the welded structures is considered, it is very important to have sufficient information about the effect of initial deflections and welding residual stresses on them. In this paper, as a fundamental study on this matter, the square plates under compression are dealt with. At first, two series of experiments were conducted, one using the specimens with initial deflection, and the other using the specimens with initial deflection and welding residual stresses. The specimens are 500×500 mm spuare plates of which thicknesses are 4.5 mm, 9.0 mm and 12.7 mm, and are simply supported along the four edges. Secondly, a series of the elastic-plastic large deflection analysis, by the finite element method, was carried out in order to clarify the effects of the shape of initial deflection, the magnitude of initial deflection, and welding residual stresses with initial deflection. It was found that the initial deflection and residual stress reduce the rigidity and ultimate strength and this tendency becomes larger for thicker plates.