Numerical strategies for complete assessment of the moment-curvature re- lationship of steel, concrete and steel-concrete composite sections

Resumo

In the non-linear evaluation of the behavior of steel, concrete and steel-concrete composite cross sec-
tions, increment and iteration strategies are necessary for the complete construction of the moment-curvature re-
lationship. For the correct simulation of sections composed of strain softening materials, a strategy of constant

force increments fails to capture the downward stretch of the moment-curvature relationship. The present study
aims to couple path-following strategies to the Strain Compatibility Method (SCM) to pass load limit points in the
construction of the relations that describe the mechanical behavior of the section. In this context, the generalized

displacement technique, depending on the generalized stiffness parameter, and the minimum residual displace-
ment method, will be adapted to the cross sectional problem. Concomitantly, strain control strategies will be

implemented as a comparison parameter, since when using it, the load limit points do not prevent the complete
construction of the cross section equilibrium paths. The constitutive relationships will be addressed explicitly as
well as the residual stresses present in the steel profiles. To validate the proposed numerical formulation, the results
obtained are compared with numerical and experimental data available in the literature.