COLLAPSE ANALYSIS OF STRUCTURES WITH MATERIAL AND GEOMETRIC NONLINEARITY BY THE FINITE ELEMENT METHOD
Carlos Javier Melchor Placencia1; Raul Rosas e Silva1; Deane Roehl1
1 Pontifícia Universidade Católica do Rio de Janeiro
doi:10.20906/CPS/CILAMCE2015-0798
Resumo
This work presents the critical load estimation of a circular shallow arch through a finite element analysis (FEA). Three kinds of techniques for collapse load estimation using FEA were employed: linear buckling, nonlinear buckling and full nonlinear analysis. For linear buckling analysis an eigenvalue linear analysis was done to estimate the critical load of ideal linear elastic structure. For nonlinear buckling analysis, eigenvalue analysis was performed for critical load in an incremental manner based on the updated stiffness matrices in order to consider material and geometrical nonlinearities. For full nonlinear analysis, the entire equilibrium path is followed up to and possibly beyond the critical load level, updating the stiffness matrix through all the incremental-iterative process. A Finite Element (FE) computational program has been developed using plane stress isoparametric bidimensional elements to perform the three previous mentioned analysis techniques. The results of the FEA show the influence of geometric and material nonlinearity in the critical load estimation. Comments are presented on the errors obtained with linear buckling analysis in determination of critical loads and buckling modes.
Palavras-chave: Finite Element; Buckling; Collapse analysis; Critical load; Nonlinear analysis