Linear model to describe the working of a three layers CLT strip slab: Experimental and numerical validation

Experimental out-of-plane, four-points bending tests were performed on two series of three-layered Cross Laminated Timber (CLT) panels made of Calabrian Beech and Calabrian Beech and Corsican Pine respectively. The predominant failure mechanism was rolling shear alongthe innerlayer and the glue line. A linear elastic model of a three-layered, CLT panel was developed to describe the stress distribution in CLT slabs in bending, with a focus on their load-bearing performance before the propagation of cracks. In the analytical model, each timber layer was defined as an Euler-Bernoulli beam. The two glue lines were modeled using extensional springs, infinitely rigid in the direction perpendicular to the beam’s axis, and with a defined stiffness in the tangential direction. The outer layers are assumed axially flexible whilethe innerone is regarded as axially rigid. The results of the proposed model were thus compared and validated with the experimental evidence and with additional FE numerical predictions given by 3D numerical simulations carried out in Abaqus.