Structural Damage Detection Utilizing Experimental Mode Shapes

• Main Author: Gerbo, Evan Jamison
• Format: Others
• Published: DigitalCommons@CalPoly 2014
• Subjects: Damage; detection; mode shape; experiment; stiffness; frame; Architectural Engineering
• Online Access: https://digitalcommons.calpoly.edu/theses/1247; https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=2334&context=theses

A method of locating structural damage is developed and tested to aid in the evaluation of structural health. This method will help minimize the cost of structural inspection and repair by informing engineers of where damage, due a seismic event, has occurred before the removal of finishes for visual inspection. This thesis begins to answer the question “can structural damage be detected solely through analysis of experimentally measured mode shapes?” The work encompasses construction of a test structure, with three braces that can be repeatedly engaged or dis-engaged, thus allowing for testing of a variety of braced configurations. For this thesis, damage is assumed to cause a change in stiffness. Experimental testing is conducted to acquire mode shapes and frequencies for the 6 dominant modes of the test structure. Lastly, the data is analyzed to identify the configuration of braces engaged on the structure. The accuracy of the method is assessed by the number of configurations that it correctly predicts and the confidence of the predictions.