Application of low-cost instrumentation and output-only modal identification techniques for the structural health monitoring of mechanical systems

Resumo

Monitoring systems are becoming more relevant to maintain the structural integrity of engineering
structures. Structural Health Monitoring (SHM) tools are getting even more important nowadays due to the need
of sustainable long-living structures. However, it is safe to say that the large costs involved on the hardware and

sensors used to apply SHM techniques are prohibitive for a large scale adoption of these tools. With the populariza-
tion of fast prototyping electronic platforms and MEMS sensors, new opportunities are showing up for industrial

applications. In this paper, an Arduino Mega 2560 board was used with ADXL335 vibration sensors in order to
monitor the structural state of a simple benchmark structure representing a two-storey building. The frequency
domain decomposition (FDD) was used to extract the mode shapes and natural frequencies of the structure by

measuring the accelerations in different locations. Damage indexes based on natural frequencies revealed the pres-
ence of the damage and its propagation. The results showed the viability of using low-cost instrumentation and

output-only modal identification techniques as alternative for the SHM of simple mechanical structures.