Stability of Structures

Problem 1. A square plate is stiffened by equidistant beams of rectangular cross-section in the loading direction. How many stiffeners are required to obtain a buckling load Nx at least the value 10 πD a . Thickness of the plate is h, which is also the width of the beam. The height of the beams is αh = 4h. The material is isotropic with Poisson’s ratio 0.3. Use the energy method and a one-parametric trial function for the deflection w(x, y). The plate is simply supported and the torsional stiffness of the beams need not to be taken into account. h = a/40, where a is the side-length of the plate.