PSI - Issue 44

Gabriele Guerrini et al. / Procedia Structural Integrity 44 (2023) 1877–1884 Gabriele Guerrini et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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modulus ( E eq,tie-down = 11732 MPa) and strength ( f y,eq,tie-down = 2.66 MPa), to return the actual axial force-displacement relationship of tie-down anchors. The contribution of the nailed OSB to the shear resistance was modelled through diagonal nonlinear elastic perfectly plastic truss elements. As shown in Fig. 3, four diagonal elements were defined and connected to top, mid height, and bottom nodes allowing the model to capture the effects of double-curvature boundary conditions. All the OSB analytical parameters are functions of panel thickness and fastener type, size, and spacing at panel edges and were determined following the recommendations provided by AWC (2015). Each truss element was given an equivalent elastic modulus E eq,OSB = 10000 MPa, from which the cross-sectional area ( A eq,OSB = 1113 mm 2 ) and strength ( f y,eq,OSB = 18.7 MPa) were calculated. Further details on the analytical derivation of mechanical properties of the specimen can be found in Damiani et al. (2022). The results of the simulation are reported in Fig. 4a. The numerical response showed an initial flexure-dominated behavior, followed by a shear-dominated one that engaged the contribution of diagonal non-linear trusses, returning a satisfactory match with the experimental results; both strength and displacement capacities were successfully captured. The amount of dissipated energy was also well captured throughout the test (Fig. 4b).

Fig. 3 Retrofitted pier numerical model schematization.

Fig. 4 Numerical validation for the retrofitted pier: a) hysteretic response comparison; b) dissipated energy comparison ( θ : drift ratio).