THE USE OF BUBBLE FUNCTIONS FOR THE STABILITY OF PLATES WITH DIFFERENT END CONDITIONS

A modified semi-analytical finite strip method of buckling analysis in which the usual restriction of two, opposite, simply supported ends i s removed by assuming appropriate longitudinal functions is described. Two sets of basic functions (denoted I and II) are used in the buckli ng study and the accuracy of these basic functions is evaluated. It is shown that the use of so-called bubble functions significantly improv es the convergence of the finite strip method for local buckling probl ems. The analytical procedure is used to investigate the local bucklin g behaviour of isotropic plates with different boundary conditions alo ng all edges under both uniaxial and biaxial compression, and the buck ling of stiffened plates under compression. The bubble formulation pro vides a powerful tool for the efficient analysis of a variety of local buckling problems. Copyright (C) 1996 Elsevier Science Ltd.