Aplicação do método da superposição modal na análise estática não linear de estruturas

Abstract

The linear buckling mode superpositon method has been utilized as an efficient procedure for geometric nonlinear static analysis of thin-type structures with a mild nonlinear pre-buckling behaviour. This work presents a modal method extension where both geometric and physical nonlinearities are considered. For problems which the mild nonlinearity condition is not satisfied, the modal solution is corrected by a procedure based on updating of the coordinate system and on tangent stiffness concept. The physical nonlinearities are represented by nonlinear springs, and the resultant modal nonlinear equation are solved by the pseudo-force technique associated with a Newton-Raphson iteration scheme. The work includes the derivations of the equilibrium equations, considerations about a software implementation, and analysis of sime application examples.