Determination Method of Bridge Rotation Angle Response Using MEMS IMU.

Hidehiko Sekiya,Chitoshi Miki,Takeshi Kinomoto

doi:10.3390/s16111882

Hidehiko Sekiya, Chitoshi Miki + Show 1 more

Open Access

https://doi.org/10.3390/s16111882

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Abstract

To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU). To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS) IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.

Highlights

In steel bridge maintenance, countermeasures for fatigue damage are important because such damage is hard to detect and may cause sudden brittle failure
In order to conduct appropriate maintenance for fatigue damage in a steel bridge, it is important to monitor bridge deformation, which consists of the displacement response and the rotation angle response, against traffic loads because such deformation is the primary source of the stress concentrations that cause fatigue damage [1,2,3]
[22] proposed proposed aa method method that that can be be used used to to determine determine bridge bridge displacement displacement usingHou inclinometers, and the results provided in can that study indicate that the proposed method is responses using inclinometers, and the results provided in that study indicate that the proposed responses using inclinometers, and the results provided in that study indicate that the highly accurate

Summary

Introduction

Countermeasures for fatigue damage are important because such damage is hard to detect and may cause sudden brittle failure. When such fatigue damage is prevented or repaired, in the case of the former, the RC slab stiffness should be strengthened, whereas in the case of the latter, the main girder stiffness should be strengthened. Gaining an understanding of bridge deformations enables the implementation of appropriate and timely maintenance and reinforcement needed to prevent fatigue damage

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Conclusion