NUMERICAL ANALYSIS OF PERFORATED STEEL PLATES SUBJECTED TO ELASTIC AND ELASTO-PLASTIC BUCKLING BY MEANS THE CONSTRUCTAL DESIGN METHOD
Caio Cesar Cardoso da Silva1; Elizaldo Domingues dos Santos1; Mauro de Vasconcellos Real1; Liércio André Isoldi1; Daniel Helbig2; Luiz Alberto Oliveira Rocha2
1 Universidade Federal do Rio Grande (FURG) - Programa de Pós-Graduação em Engenharia Oceânica (PPGEO); 2 Universidade Federal do Rio Grande do Sul - Programa de Pós-Graduação em Engenharia Mecânica
doi:10.20906/CPS/COB-2015-1204
Resumo
Steel plates are structural elements widely employed in several mechanical engineering applications. It is well known that if an axial compressive load is imposed to these plates an undesired instability phenomenon can occur: the buckling. At a certain load magnitude the limit stress is reached and the plate suffers lateral displacements (out of plane) indicating the buckling occurrence. In plates an elastic buckling or an elasto-plastic buckling can occur, depending on dimensional, constructive or operational aspects. Therefore, in the present work, the Constructal Design method was adopted to investigate the influence of the type and shape of perforations in the plate buckling. To do so, using the ANSYS® software, which is based on the finite element method (FEM), computational models were developed to tackle with the elastic (linear) and elasto-plastic (nonlinear) plate buckling. Square and rectangular thin steel plates, simply supported in its four edges, with a centered perforation, were analyzed, being the objective function to maximize the buckling limit stress, avoiding the plate buckling occurrence. The square and rectangular plates have H/L (ratio between height and length of the plate) of 1.0 and 0.5, respectively. A value of 0.15 for the cutout volume fraction (ratio between the cutout volume and the total plate volume) was considered for different types of cutout: elliptical, rectangular, hexagonal and diamond. The cutout shape variations were promoted by the H0/L0 degree of freedom (which relates the characteristic dimensions of the cutout). The results showed that the cutout shape variation has a fundamental influence in the plate buckling behavior, determining if the buckling is elastic or elasto-plastic, allowing to define a buckling stress limit curve for each perforation type. In addition, it was observed that the Constructal Design method conduct to the definition of optimal geometries and dimensions of the cutouts.
Palavras-chave: Buckling; Constructal Design; ANSYS®; Finite Element Method; Numerical Simulation