PSI - Issue 57

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

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were studied by academic and industrial partners. Details on these cases have been published by Hectors et. al. (2019), Sadeghi et. al. (2023) and Santos et. al. (2020). This R&D collaborative project did not result in a finalized SHM approach. However, several building blocks for a possible SHM approach have been developed, tested and validated. These building blocks are illustrated in Fig. 2. On the left hand side the strain measurements are represented. Optical fibre strain sensors using Fibre Bragg Grating (FBG) technology have been identified as the most suitable sensor types for industrial implementation. Multiple sensor points can be obtained on a single optical fibre line and the optical signal is not affected by electromagnetic interference. From the strain measurements events can be detected and load patterns can be identified from which a fatigue spectrum can be deduced through rainflow counting. The lifetime prediction of the structure is than performed by use of a digital twin model using finite elements to calculate the global stress distributions and local hotspot stresses.

Fig. 2: General building blocks for a SHM approach as identified in the SafeLifeproject. The images with numericalresults from the digital twin are cited from Hectors et. al. (2019).

3. Development of a SHM system for overhead cranes

3.1. Crane information

The development of the SHM system is illustrated by the case study of a crane located at the testing facilities of ArcelorMittal Global R&D Gent – OCAS NV in Zwijnaarde, Belgium. This single box girder crane, shown in Fig. 3, has a lifting capacity of 12.5 tons and a span length of 18.05 m. The crane is supported by 4 wheels, 2 at each end truck, 2.70 m apart. The load is lifted by the hoist system attached to an underslung trolley (4 wheels), which rolls over the bottom flange of the main girder of the crane. The main steel structure of the crane is categorized as class A4-E4 as per the FEM 1.001 (1998) standard.