Non-linear analysis of steel-concrete composite frames via RPHM consid- ering cracking and partial shear connection

Resumo

The present work aims at the implementation and validation of a two-dimensional numerical formulation
for the simulation of steel-concrete composite frames. Geometric and material nonlinearities are considered. A
corotational approach is used to simulate second order effects. In the case of material nonlinearity, zero-length
pseudo springs are used at the finite elements ends, where the gradual loss of flexural stiffness is determined by the
combination of normal and flexural efforts (NM) at the nodal points, exclusively. The limits of the non-cracked,
elastic and plastic regimes of the section are made in the NM interaction diagram. This diagram is obtained from
the Strain Compatibility Method (SCM), where the non-linear analysis of the cross section is made. The cracking
of the concrete is explicitly simulated with the effective moment of inertia proposed by NBR 6118 (2014). For
steel-concrete composite beams, the possibility of longitudinal sliding between the concrete slab and the steel
profile is considered, with the degradation of inertia being addressed as prescribed in NBR 8800 (2008). The
results obtained are compared with numerical and experimental data available in the literature.