Damage Assessment of Reinforced Concrete Beams using Cost Effective MEMS Accelerometers

Abstract

Damage assessment of reinforced concrete structures using vibration-based approach has been a topic of interest in civil engineering research. The adoption of these approaches in civil engineering industry is at slower pace than the other fields due to the higher degree of sophistication and higher cost of the equipment. This research is aimed at obtaining the vibration characteristics (natural frequencies) of the reinforced concrete beams using low-cost MEMS based accelerometers integrated with Arduino-based data acquisition. A three axis MEMS-based accelerometer capable of up-sampling the sampling frequency and minimizing the noise was developed using onboard analog-to-digital conversion. This accelerometer was mounted on a reinforced concrete beam and impact-based dynamic testing was carried out to determine the fundamental frequency. The obtained results were compared with the fundamental frequency determined from a commercially available accelerometer and they showed close match. Moreover, the natural frequency deterioration was also determined with increasing damage and showed close match with the similar research. Acquisition of vibration data using off-the-shelf equipment is a costly procedure. In this research, micro-electromechanical systems (MEMS) based accelerometers, combined with an Arduino-based data acquisition system, were used to acquire vibration data of a reinforced concrete beam at various damage levels. The recorded data, having lower and varying sampling frequency, were processed to find the fundamental frequency of the beam. The results showed good agreement with the commercially available accelerometers. To integrate the experimental and computational work, a finite element model also showed good agreement with the experiment. MEMS-based accelerometers are cost-effective and can be effectively employed for continuous xiv health monitoring of existing civil infrastructure. It was concluded that at a significantly low cost, MEMS-based accelerometers can be deployed in continuous vibration-based health monitoring of civil engineering structures with a great accuracy. The developed instrumentation can be expanded to many accelerometers and can be used for unattended health monitoring of civil engineering structures at a significantly lower cost than the commercially available equipment.