PSI - Issue 84

Roberto Acerbis et al. / Procedia Structural Integrity 84 (2026) 765–772

770

Sensors exhibiting persistent anomalous behavior or requiring further instrumental verification (e.g., excessive noise, significant data loss, out-of-range values, constant drift) are temporarily excluded from analysis pending further investigation and potential repair or replacement. This conservative approach is necessary to preserve overall monitoring system quality: it is preferable to rely on a smaller number of fully reliable sensors than to use compromised data that could lead to incorrect interpretations of structural condition and erroneous safety assessments. 3. Monitoring System Management Monitoring system management represents the operational synthesis of the workflow described in the previous sections, integrating data acquisition, validation, and analysis into a continuous process aimed at supporting operational and maintenance decision-making. The management workflow includes: (i) (systematic control of system status and data quality; (ii) periodic analysis of monitored quantities according to the adopted Data-Driven or Model-Based approach; (iii) production of interpretative reports; (iv) activation of codified operational procedures in case of threshold exceedance. 3.1. Management under Ordinary Operating Conditions Under ordinary operating conditions, i.e., in the absence of threshold exceedance, validated data are analyzed to verify the temporal stability of the structural response and the possible presence of evolving trends. Synthetic reports are produced at predefined intervals to document the structural condition, proper sensor operation, and the absence of significant structural criticalities. Instrumental anomalies (e.g., data loss, excessive noise, drifts) are reported to activate appropriate system maintenance activities, ensuring long-term continuity and reliability of the monitoring system. 3.2. Operational Procedure in Case of Threshold Exceedance Threshold exceedance activates extraordinary management of the structure. Thresholds are organized into increasing levels of criticality (ATTENTION, ALERT, ALARM) and are defined according to the adopted monitoring approach and expected structural performance. Upon first threshold exceedance, a preliminary verification is performed to exclude false alarms by checking data consistency and sensor functionality. Once exceedance is validated, actions associated with the reached threshold level are implemented. Exceedance of the ATTENTION threshold triggers further analyses and potential intensification of monitoring and inspection activities to improve understanding of the observed phenomenon. In Model-Based systems, recalibration of the numerical model and threshold updating may be performed. Exceedance of the ALERT threshold requires coordination between data analysis, on-site inspections, and management evaluations, potentially leading to risk mitigation measures such as temporary operational restrictions. Exceedance of the ALARM threshold indicates a potentially critical safety condition and may require immediate emergency management actions, supported by near real-time information provided by the monitoring system. Termination of threshold exceedance conditions occurs following verification of stable re-entry of monitored parameters within acceptable limits and successful completion of analysis and inspection activities. This phase may include updating thresholds and monitoring strategies within a continuous improvement framework.