PSI - Issue 57

Jeroen Van Wittenberghe et al. / Procedia Structural Integrity 57 (2024) 95–103 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

99 5

the load induces horizontal bending in the girder. Consequently, the FBG readings of the two lines present are out of phase, as depicted in Fig. 5. Monitoring horizontal bending at different points along the girder can be used, for instance, to detect crane skewing and generate alerts to the operator.

Fig. 5: Strains for sensor ID 5 in the north fibre line when the trolley is moved along the girder. Logically, as the trolley approaches the sensor position, the strain readings increase. The monitoring system can also be applied to derive the dynamic hoisting factor experimentally. This factoris used by standards like EN 13001-1-3 (13001-1-3 (2019)) and EN 1991-3 (1991-3 (1991)) to account for dynamic effects in static and fatigue strength calculations. In these standards, this factor is obtained from generic tables based on the crane stiffness class. Particularities of the crane design, which can influence the crane ’s dynamic behavior, are ignored. Applying a dynamic factor derived from the specific crane design and usage case contributes to more accurate structural and fatigue assessments. Moreover, monitoring the dynamic response can assist in defining a lifting strategy that is less impactful on the fatigue life of the crane. Fig. 6 shows strain results obtained by sensor #5 of the north fibre when a load was lifted at fast and slow hoisting speeds. Based on the measurements, the dynamic hoisting factors were derived, 1.09 for the fast speed case and 1.03 for the slow speed case.