Vibration-based damage detection research aims to develop efficient algorithms to identify structural damage from monitoring data. One of the main categories of such algorithms is data-driven techniques which extract features from measured signals, and identify the damage by evaluating the significance of potential changes in these features. This paper presents application of several data-driven damage identification methodologies on a multivariate simulated data set. First, general regression models are applied to data collected through clusters of sensors and damage sensitive features are extracted. For systems with linear topology, it is shown that substructural regression modeling can also be performed on time-and frequency-domain transforms of the measured signals to estimate local stiffness of the structure as damage features. Subsequently, change detection techniques are utilized to statistically determine the significance of changes in the extracted features in order to distinguish between assignable changes as a result of damage and common changes due to environmental factors. Finally, a toolsuite is developed to facilitate application of the developed algorithms and improve the damage identification performance through incorporation of various combinations of regression models, damage features and statistical tests.
IntroductionThe ultimate goal of vibration-based structural health monitoring (SHM) research is to develop efficient algorithms capable of detecting the time, location, and severity of any damage induced changes in structural components of monitored systems. Toward this goal, multitudes of methods have been proposed over recent decades that commonly establish a baseline for selected damage features and monitor their change from the baseline in the following unknown health conditions. Various features have been used for the purpose of damage identification; uncertain parameters of a finite element (FE) simulation of the structure that is calibrated with reference to modal quantities extracted using system identification (SID) algorithms [1,2], or features that are directly extracted from measured signals without using FE or SID procedures to train the data [3][4][5][6]. Each group of these damage identification methods has their own advantages and drawbacks. The first group is usually more laborious to implement and require certain a priori knowledge of structural properties, and location of damage; however, the calibrated model could be beneficial in design of repair scenarios or estimating the remaining life of the structure. The main advantage of the second group is their efficiency, and that they can be readily applied to measured signals without any prior information. Therefore, their application for a general automated damage detection platform is more promising. However, these data-driven methods are ineffective without statistical analyses to determine the change threshold for the extracted features. This paper presents application of multiple data-driven damage detection pr...