Conclusion
There are previous analytical expressions to describe the slip-load behaviour of a composite system, not being able to establish any relationship between the material and geometric configuration of the joint and the result obtained. Furthermore, in order to adequately describe the behaviour in the linear phase and in the plastic phase, they require the inclusion of correction factors, resulting in extremely complex expressions. The new proposal presents a simple expression that allows defining the behaviour in both phases, without needing to establish more correction factors and does so taking into account only two factors. On the one hand the geometry of the plate-timber contact zone (α) and on the other an ultimate load value (Fmax) supported by the joint. The determination of the failure mode has allowed to relate the ultimate load with the shear stress (τs) in the contact zone and with the timber shear strength (fv). It is therefore possible to establish a predictive load equivalent (Fpredict) for each geometric configuration from a given value of shear strength. Using this value in the proposed expression it is possible to predict the behaviour of the joint in load-slip terms. Therefore, this expression allows to establish a simple design rule for the determination of the slip module Ks. The proposed analytical model is therefore a design tool. The complexity of the FEM numerical model is directly related to the accuracy of its results. For stress-strain behaviour analyses it is extremely important to have a model that accurately reflects the influence of each geometric factor and each mechanical property of the constituent materials.
