PSI - Issue 78

Arash Rahimi et al. / Procedia Structural Integrity 78 (2026) 1767–1774

1769

Table 1. Bridge section properties. Element type

Length (cm)

Width (cm)

Thickness (cm)

Deck

200 200

40

0.1 0.4

Beams

1.5

Upper and Lower Support Plate 1 To control horizontal dynamic motion, each bridge support on the longitudinal edges was equipped with a diagonal steel spring, forming spring-supported boundary conditions to isolate vertical modes from lateral or torsional effects. These setup with combination of diagonal springs and vertical springs in the supports allowed the bridge to exhibit a more complex and realistic dynamic response compared to rigid supports, making it suitable for modal analysis, flexibility in damage scenario definition and structural health monitoring (SHM) experimentation Measuring Devices • Analog GY-61 Accelerometers A total of 13 analog accelerometers (GY-61 / ADXL335) were installed on the bridge and connected to an ESP32 microcontroller, which provided the highest possible sampling rate for synchronized data acquisition—approximately 550 Hz and the sensors only measure the data in Z-direction. Sensor placement was as follows (Figure 3) − 9 accelerometers were placed along one longitudinal edge of the deck, with 3 sensors per span (Acc.01 to Acc.09 at quarter, mid, and three-quarter span points) − 3 accelerometers were mounted on the opposite edge at the midpoint of each span to evaluate transverse response symmetry, (Acc.10 to Acc.11) − one central accelerometer was placed at the geometric center of the deck (Acc.13). 30 6

(a)

(b)

Fig. 3. Top view (a) and side view (b) of the bridge with sensors

These data were transmitted via serial communication to a custom Python script to handle real-time data logging, stored readings in output files and periodically updated plots and buffered data for stability.