Ferreira, PedroVirtuoso, Francisco2015-11-172015-11-172015-07http://hdl.handle.net/10400.26/10264Comunicação apresentada na 8th International Conference on Advances in Steel Structures 2015, 21-24 july 2015, Lisbon, PortugalThis paper presents a computational semi-analytical model for the post-buckling analysis and ultimate strength prediction of stiffened plates under longitudinal uniform compression. The possibility of considering fully free in-plane displacements at longitudinal edges (or unloaded edges) is the innovation of this model over existing models, where these displacements are assumed constrained to remain straight. Comparisons between the semi-analytical model results and nonlinear finite element model results are presented. This study shows that the developed semi-analytical model predicts with accuracy the elastic critical buckling stress, the buckling modes, the ultimate strength and the failure modes obtained through the nonlinear finite element method. The semi-analytical model enables versatile and comprehensive analysis of results and it is computationally efficient when compared with the nonlinear finite elements methods.engStiffened platesStabilityInteractive bucklingUltimate strengthSemi-analytical methodconference object