Estimating bridge displacement from acceleration using modal analysis and the minimum description length principle

Measuring bridge displacement for moving vehicle loads helps in load rating and evaluating the structural health of the bridge. Traditional methods of measuring bridge displacement such as laser systems and displacement transducers are expensive, require a stationary reference point and are complicated to setup. Measuring acceleration using accelerometers is inexpensive and easy. Displacement can be obtained from this acceleration, but due to noise present in the measured acceleration direct double integration results in erroneous displacement estimations. In this paper we use minimum description length to remove the noise from the acceleration and obtain correct displacement estimation using modal analysis. We also propose a method to obtain the static displacement underlying in the estimated dynamic displacement. We tested our method by measuring the acceleration of a steel beam, which is subject to a dynamic load.