Development of an ultra-low-cost wireless data acquisition system for monitoring strain and deflection

Abstract

Strain gauges are gaining popularity for monitoring stress and strain within structural elements and for detecting and identifying structural damage. Although they are relatively inexpensive, they are not as widely used as accelerometers in structural health monitoring. This is due to several factors, such as the high cost of data acquisition systems required to collect strain data and the need for a large number of gauges to monitor a structure. Therefore, this research aims to develop a low-cost wireless strain gauge data acquisition system with acceptable accuracy and a high sampling rate. This system is composed of commonly available electronic components and open-source software, with a cost of $20. The system’s precision in measuring displacement was assessed in a laboratory experiment, and further experiments were conducted on an aluminum beam to investigate its response under both static and dynamic conditions. Additionally, the accuracy of the system for measuring deflection and strain in reinforced concrete elements was assessed through a bending test on a reinforced concrete beam. The findings indicated that the developed data acquisition system can accurately measure displacement, with a root mean square error of 0.1 mm, as well as strain values within the range of a few micro-strains.