Development of a Vibration Measurement System for Bridges

Abstract

Traditionally, the bridge survey has been carried out based on visual inspections, which usually do not detect hidden structural failures. This work describes the development of a structural monitoring system to measure the bridge's dynamical behavior, to support structural verification and retro-analysis procedures. Also, the motivation for this research is the absence of cost-effective methods in Brazil to perform this structural evaluation. To define the hardware requirements, a bibliographic review about modal analysis and structural identification is carried out. Beyond the hardware project of the electronic device has considered variables associated with the operational modal analysis, and observing the steps of construction of the sensors, microcontroller, and computational communication, as well as the budget restrictions. The laboratory calibration tests were performed in order to grant the device reliability. The performance evaluation has indicated that the device is able to acquire 303 samples per second, with 16 bits precision from the three-axis, as well as to support a +-8G range. The sensors calibration was accomplished using a shaker device and calibrated PCB accelerometer attached to a high-performance data acquisition system. The device validation was performed in a bridge located in Passo Fundo, southern Brazil, which has been detailed studied in the literature