PSI - Issue 62

Laura Ierimonti et al. / Procedia Structural Integrity 62 (2024) 832–839 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The results indicate that in the absence of evidence and with the model remaining undisturbed, the most probable damage model is N0 (undamaged), the Decision-Making favors the action of doing nothing, and the risk index RI1 has a higher probability for the low level.

Fig. 3. Damage models: a) Parametric analysis as a function of intensity of damage; b) Hoteling’s Control Chart.

This suggests that the conditional probabilities in the Bayesian Network, selected by engineering expertise, have been fine-tuned to reflect a low likelihood of damage when no evidence is available. Subsequently, novelty detection updates the network, impacting both Decision-Making and risk RI1, resulting in an increased probability of repair and a shift in risk level from low to medium-low. Conversely, DM is minimally affected by novelty evidence, aligning with the data-driven nature of the information. Subsequently, based on the BIC results, the node DM-SHM is inferred. Consequently, from the DM node, the model MP3 emerges as the most feasible one. This information, in turn, triggers an increased need for a repair action and a slight elevation of index RI1.

Fig. 4. DBN results over time considering different information: a) node DM; b) node Decision Making; c) node RI1.

To underscore the potential influence of visual inspections, the results are then updated taking into account possible VI outcomes: evidence on model MP1 (as visual inspections may find it challenging to correctly identify damage models with latent defects) and evidence on the severity of damage (medium and high). The results reveal that if different DMs are identified from SHM and VI, the probabilities are adjusted accordingly, giving higher importance to both determined models. Moreover, the increase in damage severity does not affect the probabilities of the DM node but leads to an escalation in the suggested action (repair) and risk. Finally, evidence pointing to a repair action restores the structure to its undamaged condition.