May 18, 2024
Milad Jahangiri

Milad Jahangiri

Academic Rank: Assistant professor
Address: School of Engineering, Floor 2, Room 227.
Degree: Ph.D in Civil Engineering
Phone: (+98) 77 3122 2372
Faculty: Faculty of Engineering

Research

Title A procedure to estimate the Minimum Observable Damage in truss structures using vibration-based Structural Health Monitoring systems
Type Article
Keywords
Minimum observable damage Uncertain modal data Structural damage detection Receiver Operating Characteristic Vibration based SHM
Journal PROBABILISTIC ENGINEERING MECHANICS
DOI https://doi.org/10.1016/j.probengmech.2023.103451
Researchers Milad Jahangiri (First researcher) , Antonio Palermo (Second researcher) , Soroosh Kamali (Third researcher) , Alessandro Marzani (Fifth researcher)

Abstract

In this work, we propose a procedure to estimate the Minimum Observable Damage (MOD) by a vibrationbased Structural Health Monitoring (SHM) system. The MOD is defined as the smallest damage size that can be detected by an SHM system with given Probability of Detection (POD) and Probability of False Alarm (PFA). To this purpose, the MOD is computed by exploiting the Receiver Operating Characteristic (ROC) analysis, once a damage index (DI) built on monitoring data/features is defined. In particular, the MOD is defined as the damage intensity corresponding to an area under the ROC curve of 95%. The proposed idea is discussed by utilizing pseudo-experimental data generated via numerical simulations for undamaged and damaged structures. In the developed simulations, environmental uncertainties and measurement noises are considered. As case studies, we consider truss structures and use modal data, namely frequencies of vibrations and mode shapes, to build the DIs. Using the dataset of DIs, the ROC methodology is exploited to establish the probability of detecting certain damage over the probability of false alarms. For a given DI, results are provided in terms of MOD for each structural element of the truss structure considering one damaged element at a time. By establishing a relation between modal data, damage size, and POD/PFA, the proposed approach can assess the quality of the adopted DI, thus supporting the initial design of an SHM system.