Cappello Carlo, Zonta Daniele, Laasri Hassan Ait, Glisic Branko, Wang Ming
Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38122 Trento, Italy.
Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XQ, UK.
Sensors (Basel). 2018 Feb 5;18(2):466. doi: 10.3390/s18020466.
The recent developments in measurement technology have led to the installation of efficient monitoring systems on many bridges and other structures all over the world. Nowadays, more and more structures have been built and instrumented with sensors. However, calibration and installation of sensors remain challenging tasks. In this paper, we use a case study, Adige Bridge, in order to present a low-cost method for the calibration and installation of elasto-magnetic sensors on cable-stayed bridges. Elasto-magnetic sensors enable monitoring of cable stress. The sensor installation took place two years after the bridge construction. The calibration was conducted in two phases: one in the laboratory and the other one on site. In the laboratory, a sensor was built around a segment of cable that was identical to those of the cable-stayed bridge. Then, the sample was subjected to a defined tension force. The sensor response was compared with the applied load. Experimental results showed that the relationship between load and magnetic permeability does not depend on the sensor fabrication process except for an offset. The determination of this offset required in situ calibration after installation. In order to perform the in situ calibration without removing the cables from the bridge, vibration tests were carried out for the estimation of the cables' tensions. At the end of the paper, we show and discuss one year of data from the elasto-magnetic sensors. Calibration results demonstrate the simplicity of the installation of these sensors on existing bridges and new structures.
测量技术的最新发展促使世界各地许多桥梁和其他结构安装了高效的监测系统。如今，越来越多的结构已建成并配备了传感器。然而，传感器的校准和安装仍然是具有挑战性的任务。在本文中，我们通过一个案例研究——阿迪杰桥，来介绍一种在斜拉桥上校准和安装弹性磁传感器的低成本方法。弹性磁传感器能够监测拉索应力。传感器安装在桥梁建成两年后进行。校准分两个阶段进行：一个在实验室，另一个在现场。在实验室里，围绕一段与斜拉桥拉索相同的拉索制作了一个传感器。然后，对样本施加规定的拉力。将传感器的响应与施加的载荷进行比较。实验结果表明，除了一个偏移量外，载荷与磁导率之间的关系不依赖于传感器的制造过程。安装后需要进行现场校准来确定这个偏移量。为了在不将拉索从桥上拆除的情况下进行现场校准，进行了振动测试以估算拉索的张力。在论文结尾，我们展示并讨论了弹性磁传感器一年的数据。校准结果证明了在现有桥梁和新结构上安装这些传感器的简便性。
