Detection and Estimation of Damage in Framed Structures Using Modal Data

The inevitable ageing and degradation of buildings and the structural failures that follow, have ignited a need for early prognosis of probable structural failures so that proactive measures can be undertaken. Hence, one of the important steps of structural health monitoring (SHM) process is the detection of damage location and estimation of damage severity. Modal data can be effectively used for this purpose owing to their sole dependency on mechanical characteristics of a structure. This study presents a damage detection methodology based on mode shape derivatives such as mode shape slope (MSS) and mode shape curvature (MSC) for a symmetric experimental steel frame model. Furthermore, an extended parametric analysis has been performed using a calibrated finite element model to investigate damage localization and quantify severity. The study provides key conclusions about the effect of boundaries on the damage detection method for the steel frame model. Furthermore, damage detection using MSC is identified to be more sensitive as opposed to MSS method.