A fem-based approach coupled to path-following strategies for non-linear anaylis of steel-concrete cross-sections

Resumo

The present study aims at the non-linear analysis of steel-concrete composite cross-sections. The strain

compatibility method (SCM) is used to describe the sections deformed shape in each step of the incremental-
iterative solution process. Four-node quadrilateral finite elements (FE) are implemented to compose the FE mesh

of the analyzed sections. For the full analysis of the moment-curvature relationship, the SCM is coupled to path-
following strategies (adapted generalized displacement technique and adapted minimum residual displacement

method) to go beyond the critical bending moment points in the construction of the relations that describe the

complete cross-section mechanical behavior. Concomitantly, the strain-control strategy is implemented as an al-
ternative numerical approach and used for comparison, since the bending moment limit points do not prevent the

complete construction of the cross-section equilibrium path. The constitutive relationships are addressed explicitly,
as well as the residual stresses present in the steel sections. To validate the proposed numerical formulation, the
results obtained are compared with the numerical and experimental data available in the literature.