Nonlinear analytical model of a two-layer wooden beam in a heritage structure

• A nonlinear analytical model of a two-layer cantilevered beam is built.
• This model has four scenarios by considering friction–slip–shear at the interface.
• The model enables a practical analysis without applying the friction–slip stiffness.
• The deformation and energy dissipation under different types of loads are studied.

Existing heritage wooden structures in China have a common structural component which composes of layers of wooden beam to resist the vertical applied load. The performance of this type of component under load is not clear particularly under the seismic effect. This paper presents a nonlinear analytical model of a two-layer wooden beam system based on Euler–Bernoulli beam theory. The proposed model takes into account the effect of the friction–slip–shear between the two individual layers with a specified range of slip. There are four deformation scenarios to provide the load resistance based on the state of friction between the two layers and the state of shear at the connector (tenon). The behavior of the tenon with the friction–slip–shear mechanism is significant to the mechanical behavior of the two-layer beam system. This analytical study aims at evaluating the frictional stiffness of a two-layer wooden beam, and an implicit formulation on the frictional stiffness of the system is presented. Its effect on the lateral deformation when subjected to four kinds of loadings is studied. The hysteresis curve is then plotted for different kinds of pseudo-dynamic external loads to illustrate the energy dissipation capacity of this type of joint in Tibetan structures.