*3.2. Material Properties*

The mechanical response of both timber and steel components is described with the support of constitutive laws and material models available in the ABAQUS library. An isotropic, elastic-plastic Von Mises constitutive law is used for carbon steel screws (10.9 the nominal resistance class), with *E* = 210 GPa and ν = 0.3 as nominal modulus of elasticity (MoE) and Poisson' ratio. Based on [6], the yielding/ultimate stress values are set in *f* <sup>y</sup> = *f* <sup>u</sup> = 940.3 MPa. An ultimate strain δ<sup>u</sup> = 0.5% is considered. At the same time, an orthotropic constitutive law is used for spruce [21]. To ensure more realistic behaviours for the timber members, this constitutive law is integrated with a Hill plastic criterion and a brittle failure parameter. The Hill criterion allows to account for different resistance values in the principal directions of timber, and thus for different potential critical mechanisms for the examined PO setup. The additional brittle failure law, moreover, is used to include possible crushing phenomena in the timber close to the fasteners. Once attained the ultimate resistance *f* c,90, a linear propagation of compressive damage is taken into account for timber. Due to lack of more detailed experimental feedback, this material degradation is set to maximize at a failure deformation of δ<sup>u</sup> = 4mm. This value is adapted from [20], where C24 timber members have been investigated, based on the similarity in the resistance parameters for GL24h spruce. The final input parameters for timber are listed in Table 1, based on the nominal mechanical properties for GL24h strength class [24,25].


**Table 1.** Input mechanical properties for GL24h strength class timber (ABAQUS/Explicit).

Finally, the equivalent soft layer in Figure 5 is mechanically characterized in accordance with [20,21], in the form of an indefinitely linear elastic material with GL24h input properties (Table 2).


**Table 2.** Input mechanical properties for the soft layer and for the CZM contact interaction (ABAQUS/Explicit).
