title: Technique for Determining Bridge Displacement Response Using MEMS Accelerometers.
abstract: In bridge maintenance, particularly with regard to fatigue damage in steel bridges, it is important to determine the displacement response of the entire bridge under a live load as well as that of each member. Knowing the displacement response enables the identification of dynamic deformations that can cause stresses and ultimately lead to damage and thus also allows the undertaking of appropriate countermeasures. In theory, the displacement response can be calculated from the double integration of the measured acceleration. However, data measured by an accelerometer include measurement errors caused by the limitations of the analog-to-digital conversion process and sensor noise. These errors distort the double integration results. Furthermore, as bridges in service are constantly vibrating because of passing vehicles, estimating the boundary conditions for the numerical integration is difficult. To address these problems, this paper proposes a method for determining the displacement of a bridge in service from its acceleration based on its free vibration. To verify the effectiveness of the proposed method, field measurements were conducted using nine different accelerometers. Based on the results of these measurements, the proposed method was found to be highly accurate in comparison with the reference displacement obtained using a contact displacement gauge.
authors.affiliation: Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Setagaya 158-0082, Japan. hsekiya@tcu.ac.jp.
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Sekiya
authors.affiliation: Urban and Civil Engineering, Tokyo City University, 1-28-1 Tamazutsumi, Setagaya 158-8557, Japan. tyler.durden.kk.999@gmail.com.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Tokyo City University, 1-28-1 Tamazutsumi, Setagaya 158-8557, Japan. cmiki@tcu.ac.jp.
authors.forename: Chitoshi
authors.initials: C
authors.lastname: Miki
keywords: bridge health monitoring; free vibration separation method; measurement error; microelectromechanical systems accelerometer; vehicle detection