Finite element modeling of frames considering the physical and geometric nonlinearity

Abstract

With advances in technology, the degree of safety obtained and the low cost of computational researches, compared with experimental tests, have enabled the application of numerical techniques for solution of nonlinear problems of structures. The damage constitutive models have been used as an important tool to analyze the structures stiffness loss in order to prevent the material degradation. This paper presents a formulation by means of Finite Element Method considering physical and geometric nonlinearities for the analysis of plane frames. The behavior of the material is described by a model based on Continuum Damage Mechanical. In obtaining the internal force vector, the equivalent flexural stiffness modulus is obtained by dividing the cross section in layers. In order to trace the equilibrium path with limits points of the structure it is used the Chebyshev iterative method, with cubic convergence rate, associated to the Generalized Displacement Control strategy. Numerical results found in literature are compared with those obtained by computational code developed. The proposed modeling presents potentiality in the simulation of the ultimate strength of frame type structures.

Keywords

• mecânica do dano contínuo
• elementos finitos
• técnica de continuação
• não linearidade geométrica