A family of interface elements for the analysis of composite beams with interlayer slip

This work presents the numerical formulation of a family of zero-thickness interface elements developed for the simulation of composite beams with horizontal deformable connection, or interlayer slip. The proposed elements include formulations to be employed with Euler–Bernoulli as well as with Timoshenko beam theories, combined to displacement-based beam elements sharing the same degrees of freedom. The elements may be employed for the simulation of steel–concrete composite beams, layered beams or other structural systems in which components are connected with the possibility of interlayer slip. Numerical examples are provided to assess the accuracy and robustness of the formulations and to identify the most reliable formulations. Abnormal slip distributions are shown to occur also with the Timoshenko-based elements, usually in conjunction with transverse shear locking.