CONFIABILIDADE DE PLACAS FINAS DE A O SOB FLAMBAGEM

In this paper, the nonlinear buckling analysis of thin steel plates using the finite element methodwas performed. The Method of Spectral Representation of the Stochastic Field was used to generate thegeometric imperfections of the plate. The ANSYS finite element program was used to calculate the bucklingcritical load and the rupture load of the plate. The Monte Carlo method was applied to analyze the effectthat the variability of the imperfections stochastic field and the random variables (modulus of elasticity,yield stress and thickness) have on the variation of the plate’s rupture load. A reliability analysis of the platewas also carried out. First the finite element model was validated through the analytical solution of Paik etal. (2001), for the post-buckling behavior of a plate; and the numerical solution of Kumar et al. (2007),for a plate with a rectangular hole. After, the effect of variability was studied for the situation in which theimperfections stochastic field and the random variables are considered as varying together. The analysis ofreliability was based on the relation Buckling Strength Ratio (BSR), between the plate’s rupture load and itselastic buckling critical load. The main findings are: that the effect of the joint variability is significant andthat for the plate analyzed here, when the value of BSR is equal to 2.2, the reliability is practically 100%,but when the value of BSR is higher than 3.8, the reliability vanishes.