Approximate buckling strength analysis of arbitrarily stiffened, stepped plates

A computationally efficient method for the elastic buckling and buckling strength analysis of in-plane biaxial and shear loaded stiffened plates with varying, stepwise constant thickness is presented. The main focus is on biaxial loading cases. The stiffeners may be sniped or end-loaded (continuous), and their orientations may be arbitrary. Both global and local plate buckling modes are captured. The method is semi-analytical and makes use of simplified displacement computations that involve the elastic buckling load (eigenvalue), determined using a Rayleigh–Ritz approach, and finally stress computations using large deflection theory in combination with strength assessment using von Mises’ yield criterion as applied to membrane stresses. The displacements are represented by trigonometric functions, defined over the entire plate. The method is implemented into a Fortran computer program, and numerical results, obtained by the method for a variety of plate and stiffener geometries, are compared with corresponding fully nonlinear finite element analysis results. An extension to strength analysis that also includes lateral loading is discussed.