Performing Structural Assessment using Acoustic Measurements

Abstract

Natural hazards, such as earthquakes, could be catastrophic. One challenge that society faces is how to provide a rapid and accurate evaluation of the structural damages after the events. Traditional visual inspection is useful, but it may not provide a subjective and consistent assessment. To overcome that, researchers have focused on designing and employing health monitoring systems on structures, in which various sensors are installed to obtain measurements to perform monitoring evaluations. Typically, either wired and/or wireless sensor networks are installed in these systems, where the deployment and operation costs are obstacles to their usage. This study attempts to use infrasound measurements obtained from microphones to identify low-frequency modal properties (e.g., natural frequencies and mode shapes) of structures. A two-story structural model subjected to ground excitations is utilized as a testbed to investigate feasibility. Various approaches are proposed to improve the signal-to-noise ratio of the microphone measurements. The results confirmed the possibility of using infrasound measurements as a means to perform non-contact and non-destructive structural health monitoring for civil structures.