Vibration Analysis and Digital Image Correlation Techniques for a Suspension Bridge

Abstract

Bridge inspection is critical to safe transportation, especially in highly urbanized areas. Frequent inspection invoked by the un-scheduled maintenance for bridges is often subjected to the availability of NDT service providers. Hence the objective of the current research is to provide an economical NDT technique for the maintenance crew. Digital image correlation techniques can be cost-effective for the displacement measurement of highway bridges using merely one high-resolution camera. The vibration analysis based on the remote measurements of high-speed camera systems is not only challenging but also prohibitively expensive. An alternative approach using two consumer-grade digital cameras has been developed. The field test has been successfully carried out for a 50-meter-span suspension bridge. Satisfactory results have been obtained in both the vertical displacement caused by a moving load and the mode shapes of the first and second vibration modes.