Optimal layout of sensors in large-span cable-stayed bridges subjected to moving vehicular loads

Qingfei Gao,Jun Li,Binqiang Guo,Kemeng Cui,Yang Liu

doi:10.1177/1550147719899376

Abstract

To obtain the health status of long-span cable-stayed bridges, multiple sensors are applied to the health monitoring system for data collection. The optimal layout of sensors that aims to obtain as much structural information as possible with fewer sensors is important to ensure the effectiveness of the health monitoring system. Sensors are usually placed in typical locations where the structural response is obvious, and most studies utilize static response for the determination of sensor location. In fact, bridges primarily suffer the dynamic load, of which the response has a significant impact on the structural health. In this article, an optimal sensor layout method for a long-span cable-stayed bridge based on dynamic response is proposed under the consideration of vehicle–bridge coupled vibration. With vehicle load applied onto different lanes, the dynamic responses of different bridge members are obtained, and the number and the location of cable force sensors are determined according to the distribution of cable dynamic coefficient DC, and the number and the location of displacement and strain sensors are determined according to the distribution of DGD and DGM, which are the dynamic load allowance for girder deflection and bending moment, respectively. The results prove that this method can reduce the number of sensors effectively and obtain bridge state information more perfectly.

Highlights

Bridges play an important role in the transportation system
Taking the force characteristics of different parts of a cable-stayed bridge under vehicle loads into consideration, an optimal sensor placement (OSP) method based on vibration mode and dynamic response for long-span cable-stayed bridges is proposed in this article
Considering that the bridge structure is mainly subjected to dynamic loads, an optimal layout of sensors for long-span cable-stayed bridges based on vehicle– bridge coupling vibration analysis is proposed in this article

Summary

Introduction

Bridges play an important role in the transportation system. In recent years, the span of bridges has become larger and the structural form has become more complicated. Taking the force characteristics of different parts of a cable-stayed bridge under vehicle loads into consideration, an OSP method based on vibration mode and dynamic response for long-span cable-stayed bridges is proposed in this article. 1⁄2MV ÈZ€V É + 1⁄2CV ÈZ_ V É + 1⁄2KV fZV g = fFV g ð5Þ in which {FV} denotes the load vector induced by the bridge and [MV], [CV], and [KV] denote the mass matrix, damping matrix, and stiffness matrix of the vehicle, respectively. The mass matrix, displacement vector, and load vector of the vehicle model are, respectively, shown as follows in which Di denotes the relative displacement of the contact point between wheel and bridge deck and kti and cti denote, respectively, the stiffness coefficient and damping coefficient of the ith vehicle wheel.

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Conclusion