Development of displacement estimation method of girder bridges using measured strain signal induced by vehicular loads

2019 ◽  
Vol 186 ◽  
pp. 203-215 ◽  
Author(s):  
Jun-Chang Jeon ◽  
Hee-Hyun Lee
Keyword(s):  
Estimation Method ◽  
Displacement Estimation ◽  
Girder Bridges ◽  
Measured Strain ◽  
Strain Signal

scholarly journals Development of a Reference-Free Indirect Bridge Displacement Sensing System

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5647
Author(s):  
Jongbin Won ◽  
Jong-Woong Park ◽  
Junyoung Park ◽  
Junsik Shin ◽  
Minyong Park
Keyword(s):  
Estimation Method ◽  
Reference Points ◽  
Maximum Displacement ◽  
Moving Vehicle ◽  
Displacement Estimation ◽  
Sensing System ◽  
Girder Bridges ◽  
Sensor Platform ◽  
Load Carrying ◽  
Vehicle Loads

Bridge displacement measurements are important data for assessing the condition of a bridge. Measuring bridge displacement under moving vehicle loads is helpful for rating the load-carrying capacity and evaluating the structural health of a bridge. Displacements are conventionally measured using a linear variable differential transformer (LVDT), which needs stable reference points and thus prohibits the use of this method for measuring displacements for bridges crossing sea channels, large rivers, and highways. This paper proposes a reference-free indirect bridge displacement sensing system using a multichannel sensor board strain and accelerometer with a commercial wireless sensor platform (Xnode). The indirect displacement estimation method is then optimized for measuring the structural displacement. The performance of the developed system was experimentally evaluated on concrete- and steelbox girder bridges. In comparison with the reference LVDT data, the maximum displacement error for the proposed method was 2.17%. The proposed method was successfully applied to the displacement monitoring of a tall bridge (height = 20 m), which was very difficult to monitor using existing systems.

scholarly journals Research on the estimation method of the point-of-interest (POI) displacement for ultra-precision flexible motion system based on functional optical fiber sensor

2021 ◽  
Vol 22 ◽  
pp. 48
Author(s):  
Yujie Li ◽  
Ming Zhang ◽  
Yu Zhu
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Estimation Method ◽  
Fiber Optic Sensor ◽  
Fiber Sensor ◽  
Optic Fiber ◽  
Estimation Model ◽  
Fiber Sensors ◽  
Optimal Position ◽  
Displacement Estimation

This paper proposes a POI displacement estimation method based on the functional optical fiber sensor and the phase modulation principle to improve the POI displacement estimation accuracy. First, the relation between the object deformation and the optic fiber lightwave phase is explained; the measurement principle of functional optical fiber sensor based on the heterodyne interference principle and its layout optimization method is proposed, and a POI displacement estimation model is presented based on the data approach. Secondly, a beam is taken as the simulation object, the optimal position and length of the optical fiber sensor are determined based on its simulation data. Finally, the experimental device is designed to verify the effectiveness of the POI displacement estimation method based on the optic fiber sensors. The frequency-domain plot of the signals shows that the optical fiber sensors can express the flexible deformation of the analyzed object well. The POI displacement estimation model with the fiber optic sensor signals as one of the inputs is constructed. Through estimating the test data, the error using the optical fiber sensor-based POI displacement estimation method proposed in this paper reduces by more than 61% compared to the rigid body-based assumption estimation method.

scholarly journals Dynamic Displacement Estimation for Long-Span Bridges Using Acceleration and Heuristically Enhanced Displacement Measurements of Real-Time Kinematic Global Navigation System

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5092
Author(s):  
Kiyoung Kim ◽  
Hoon Sohn
Keyword(s):  
Kalman Filter ◽  
Large Scale ◽  
Reduction Method ◽  
Estimation Method ◽  
Sampling Frequency ◽  
Displacement Measurement ◽  
Dynamic Displacement ◽  
Displacement Estimation ◽  
Gnss Receiver ◽  
Civil Infrastructures

In this paper, we propose a dynamic displacement estimation method for large-scale civil infrastructures based on a two-stage Kalman filter and modified heuristic drift reduction method. When measuring displacement at large-scale infrastructures, a non-contact displacement sensor is placed on a limited number of spots such as foundations of the structures, and the sensor must have a very long measurement distance (typically longer than 100 m). RTK-GNSS, therefore, has been widely used in displacement measurement on civil infrastructures. However, RTK-GNSS has a low sampling frequency of 10–20 Hz and often suffers from its low stability due to the number of satellites and the surrounding environment. The proposed method combines data from an RTK-GNSS receiver and an accelerometer to estimate the dynamic displacement of the structure with higher precision and accuracy than those of RTK-GNSS and 100 Hz sampling frequency. In the proposed method, a heuristic drift reduction method estimates displacement with better accuracy employing a low-pass-filtered acceleration measurement by an accelerometer and a displacement measurement by an RTK-GNSS receiver. Then, the displacement estimated by the heuristic drift reduction method, the velocity measured by a single GNSS receiver, and the acceleration measured by the accelerometer are combined in a two-stage Kalman filter to estimate the dynamic displacement. The effectiveness of the proposed dynamic displacement estimation method was validated through three field application tests at Yeongjong Grand Bridge in Korea, San Francisco–Oakland Bay Bridge in California, and Qingfeng Bridge in China. In the field tests, the root-mean-square error of RTK-GNSS displacement measurement reduces by 55–78 percent after applying the proposed method.

Estimation Method for Prestress Loss of Externally Prestressed Composite Girder Bridges

2014 ◽  
Vol 919-921 ◽  
pp. 547-550
Author(s):  
Yong Ming Zhao ◽  
Hong Xue Li ◽  
Xue Wei Wang
Keyword(s):  
Estimation Method ◽  
Design Parameters ◽  
Prestress Loss ◽  
Temperature Changes ◽  
Concrete Shrinkage ◽  
Girder Bridges ◽  
Composite Girder ◽  
Prestressing Loss ◽  
Simplified Calculation ◽  
Prestressing Tendon

To accurately calculate the prestress of externally prestressed composite girder bridges, the six critical factors (the prestressing tendon withdrawal and anchor deformation, friction between prestressing tendon and deviator, prestressing tendon relaxation, concrete creep, concrete shrinkage and temperature changes) that cause the prestress loss of such type of the bridges are summarized and the corresponding simplified calculation methods are respectively derived on the basis of the existing researches. The prestressing tendons ability has an important influence on the mechanical behavior of prestressed composite girder bridges, which is the key design parameters. Prestress loss will occur in the process of long-term use, so that the whole beam stress redistribution occurs. How to accurately calculate the value of the prestressing loss is an issue of great concern to engineers. And at present there is few research for prestressed composite girder bridges. On the basis of existing research, this paper summarizes the key factors that lead to loss of prestress and derives the corresponding simplified calculation method for design reference.

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