A steel-concrete composite beam element with material nonlinearities and partial shear interaction

This paper presents the formulation of a novel force-based 1D steel-concrete composite element that captures material nonlinearities and partial shear interaction between the steel profile and the reinforced concrete slab. By decomposing the material total strain into its elastic and inelastic components, a total secant solution strategy based on a direct iterative scheme is introduced and the corresponding solution strategy is outlined. A composite Simpson integration scheme, together with piecewise interpolation of the slip strain along the element axis, is employed to calculate the slip forces along the element axis consistently. The accuracy and efficiency of the formulation are verified by some numerical examples reported elsewhere in the literature, and it is shown that the formulation with just one element can lead to virtually closed form analytical results as long as the integrals in the formulation are calculated accurately.