A numerical model based on nonconvex–nonsmooth optimization for the simulation of bending tests on composite slabs with profiled steel sheeting

Abstract

It is well known that the calculation of the ultimate strength of composite concrete slabs with profiled steel sheeting requires the determination of the longitudinal shear resistance which depends on the quality of the bond at the steel sheeting–concrete interface. According to Eurocode 4, the longitudinal shear strength of the composite concrete slabs is calculated through analytical relationships which are based, however, on coefficients determined experimentally through a series of full-scale bending tests. In this paper a numerical model is proposed that is able to simulate the above experimental procedure. For the modeling of the shear bonding between the concrete and the profiled sheeting, a nonmonotone law involving vertical and softening branches is used. The parameters describing this law are calculated exploiting experimentally obtained values. However, this complex shape of the shear bonding law leads to a hemivariational inequality mathematical formulation. For its numerical treatment, a numerical procedure is presented that uses tools from the theory of nonconvex–nonsmooth energy optimization. The results obtained by the proposed methodology are compared with those obtained by experimental testing. It is found that the numerical results are in a good agreement with the corresponding experimental ones.