Thursday, November 14, 2013
Mechanical and Civil Engineering Seminar
Damage Detection in Civil Structures Using High-Frequency Seismograms
Vanessa Heckmann, Mechanical and Civil Engineering, California Institute of Technology
Structural health monitoring (SHM) and damage detection methods provide a means to assess the structural integrity and safety of a civil structure following a seismic event. The application of high-frequency seismograms for damage detection in civil structures is investigated. A novel method for SHM is developed and validated using small-scale experimental testing and numerical testing. The method is designed to extract features from high-frequency acceleration records that may indicate the presence of damage. As short-duration high-frequency signals (i.e., pulses) can be indicative of damage, this method relies on the identification and classification of pulses in the acceleration records. The method is successfully applied to a small-scale experimental shear beam that is dynamically excited at its base using a shake table and damaged by loosening a screw to create a moving part. Although the damage is aperiodic and nonlinear in nature, the damage signals are accurately identified, and the location of damage is determined using the amplitudes and arrival times of the damage signal. Application of the method to full-scale structures in situ is discussed.