A force-based frame finite element formulation for analysis of two- and three-layered composite beams with material non-linearity

• Formulation of a forced-based FE model with discrete non-linear springs.
• Non-linear analysis of two- and three-layered composite beams with partial interaction.
• Development of an accurate FE model with high convergence rate.
• Capturing full short-term response of timber–concrete composite beams.

Presented in this paper is a formulation for an efficient frame finite element (FE) model for the non-linear analysis of timber–concrete and timber–timber composite structures. The element formulation is based on force interpolation concept and takes advantage of discrete non-linear springs to model the shear deformability between layers. The material non-linearity is taken into account, where the geometrical non-linearities are ignored. The developed formulation and analytical tool are employed to predict the ultimate loading capacity and load–deflection response of some experimental tests taken from the literature. The comparison between experimental results and numerical simulation shows the accuracy of the proposed model.