Modelos empíricos de resistencia al cortante y rigidez para conexiones de tornillos en X en estructuras compuestas de madera-concreto

In the literature, experimental data on X-shaped screw connections have been analyzed in order to develop an empirical model for their shear force capacity and stiffness, which are important parameters in designing timber-concrete composite structures. Although considerable research has been conducted worldwide to understand the composite action of timber and concrete, there is no generic model for determining the shear force capacity and stiffness of screw connections; most of the existing models are based on theoretical derivations. In this paper, empirical models are derived to determine the shear capacity of screw connections installed in X-shaped arrangements, considering the embedment and withdrawal strength of the screws within the timber and concrete. Moreover, a stiffness model based on global flexibility, as influenced by the material properties of timber, concrete, and screws, is elaborated. The model is validated using existing push-pull data and variations in material properties. A comparison with a well-known model demonstrates the suitability of our proposal. This model can be used to predict the shear force capacity and stiffness of X-shaped screw connections in timber-concrete composite structures.