PSI - Issue 78

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

1773

Figure 10 shows the processed LDR (Laser–LDR) sensor readings recorded during the passage of the test vehicle(s). The signal drops correspond to the interruption of the laser beam by the vehicle body and axles, enabling detection of vehicle type, axle count, and precise speed estimation. This data was synchronized with acceleration measurements to accurately align load position and bridge vibration response.

Fig. 9. LDR values of the laser to detect vehicle type, number of axles and speed Figure 11 presents the acceleration time history recorded by the accelerometers during the passage of a moving vehicle at a defined speed and mass configuration. The signal illustrates the transient dynamic response of the bridge, clearly highlighting the excitation induced by each axle and the decay of free vibration once the load leaves the span.

Fig. 10. Acceleration data of bridge subjected to single moving vehicle [C09]