PSI - Issue 78

Virginio Quaglini et al. / Procedia Structural Integrity 78 (2026) 105–112

108

( )= (2 ) =2

(1)

(2) Fig. 4 shows the displacement histories considered in the experimental program and characterized by 3 loading cycles in accordance with the requirements of the European code (CEN 2009).

Time (s)

(a)

(b)

(c)

(d)

Fig. 4. Sinusoidal displacement histories with frequencies of (a) 0.0266 Hz, (b) 0.133 Hz, (c) 0.265 Hz, (d) 0.398 Hz.

2.4. Thermal conditioning The DCSS was conditioned prior to each test in the environmental chamber of ESQUAKE Seismic Isolator Test Laboratory shown in Figure 5(a). The chamber has plan dimensions of 3x3x3 m, and its maximum and minimum temperature capacities are +50 °C and -40 °C, respectively. The controller of the chamber shown in Figure 5(b) allows to control the temperature within a tolerance of ±1 °C for the desired exposure duration.

environmental chamber

(a)

(b)

Fig. 5. (a) environmental chamber; (b) controller unit of the chamber.

Ten K-type thermocouples (Fig. 6) were used to monitor the temperature of the specimen during the exposure duration and throughout the test. Eight thermocouples (labeled as t 1 -t 8 ) were embedded in holes drilled in the top plate of the DCSS. The probes of these thermocouples were in contact with the rear surface of the concave stainless-steel sheet. In this way, it was possible to monitor the instantaneous temperature of the sliding surface in the area crossed by the sliding during the test. Two additional thermocouples (t 9 and t 10 ) were used to track the surface temperature of the concave stainless-steel at points outside the crossed area. Moreover, t 9 and t 10 were also used to check whether the temperature of the sliding surface of DCSS fit the target temperatures considered in the experimental campaign. The connectors of the thermocouples were positioned through channels shown in Fig. 6 and plugged in the data acquisition system employed to record the temperature data.