Joints and wood shear walls modelling I: Constitutive law, experimental tests and FE model under quasi-static loading

This study is the first of two companions papers that present a finite element (FE) model of timber-frame structures. It introduces a versatile hysteretic constitutive law developed for various joints with steel fasteners commonly used in timber structures (nails, screws, staples, bracket-type 3D connectors, punched plates). Relative to previous models available in the literature, the proposed model improves numerical robustness and represents a step forward by taking into account the damage of joints with metal fasteners. More than 300 experimental tests are carried out on joints and used to calibrate the constitutive law for nails and bracket-type 3D connectors. An average calibration method is presented to take into account the experimental variability. 14 experimental tests are performed on different configurations of shear walls and are used to validate the proposed FE model. Both monotonic and reversed cyclic loadings are used in these quasi-static tests. The FE model predictions are in good agreement with the experimental results. The second paper will present dynamic experiments and numerical predictions of the tests, as well as the development and validation of a computationally efficient simplified modelling of timber-frame structures based on a simplified finite element model for shear walls.