A hybrid approach to using local strain and rotation detected by nonlinear FE analyses as additional threshold values in SHM systems

Vibration-based Structural Health Monitoring (SHM) systems are susceptible to false alarms, particularly due to environmental influences. This study proposes that nonlinear static pushover Finite Elements (FE) analysis outputs can be used as complementary data to existing methods in Smart Building (SB) decision support systems. The proposed hybrid approach has the potential to reduce false alarm rates compared to decision-making based solely on modal parameter changes, statistical methods, and machine learning. To this end, in addition to these approaches, a secure proposal based on traditional procedures for integrating nonlinear structural analysis results into intelligent SHM systems is presented. A global performance evaluation of a core system was conducted to obtain local damage distribution and degrees at the element level. In the SHM system, the focus was on using element damage level thresholds obtained from system analysis as threshold values, rather than general limits in standards or solely the results of the structural system's specific global performance analysis. Today, thanks to advancements in hardware and software technologies, performing and disseminating these analyses is much easier than in the past. In the near future, the information obtained from these analyses will inevitably be further utilized in SHM systems. Although the study did not include experimental validation and model updating, it was shown that using the proposed physical thresholds in conjunction with existing modal-based SHM methods has the potential to reduce false alarm rates and provides a theoretical basis for rapid decision-making mechanisms after earthquakes.