PSI - Issue 44

Alessia Monaco et al. / Procedia Structural Integrity 44 (2023) 1925–1932 Monaco et al. / Structural Integrity Procedia 00 (2022) 000–000

1928

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point of application of the sliding force is α 1 = 61°. Therefore, in this solution, F d,1 = 275.7 kN; F pc,1 = 109.9 kN; t s,1 = 0.523; F pc,d,1 = 57.5 kN.

a

b

Fig. 1. Solution A: crossed slotted holes: (a) general scheme (dimensions in millimetres); (b) mesh of the FE model.

3.2. Solution B: device with curved slotted holes The conception of the damping device is depicted in Fig. 2. Five bolts collocated on two rows are used and curved slotted holes are designed, with rotation centre C 2 indicated in the same figure. This system presents two main differences with respect to the previous one: on the bottom, vertical and horizontal holes are replaced by curved slotted holes while, on the top, the pin connection is substituted by a bolted connection with T-stub and C-shaped steel profile. More in detail, the curved geometry of the holes of the lower central plate allows the device to rotate keeping the bolts in their initial position even during the rotation; moreover, the cross-section of the T-stub web is made weaker by means of two 20 mm diameter holes aimed at favouring the activation of the centre of rotation of the system by means of a plastic hinge. A series of studs with variable inclination are introduced for increasing the stiffness between the concrete core of the beam and the central plate with curved slotted holes. The preloaded bolts in the friction central connection are M18 class 10.9 (A res,2 = 192 mm 2 ; f ub,2 = 1000 MPa). In this case, the angle α 2 = 68° and the internal lever arm is z 2 = 380 mm. Therefore, in this solution, the following design parameters are calculated: F d,2 = 289.5 kN; F pc,2 = 134.4 kN; t s,2 = 0.538; F pc,d,2 = 72.3 kN.

a

b

M18

Fig. 2. Solution B: curved slotted holes: (a) general scheme (dimensions in millimetres); (b) mesh of the FE model.