Usage of MEMS Capacitive Acceleration Sensors for Structural Monitoring

Abstract

Bridge Structural Monitoring has been a recurring topic over the last few years. A focus has been placed on avoiding any future catastrophic bridge collapses by having a better understanding of the mechanical reactions caused by traffic and environmental conditions. This desire for a better understanding has caused a rise in the usage of sensor technologies which measure the vibrations of a structure.

The IEPE (Integrated Electronic Piezoelectric) or MEMS Capacitive technologies are widely used accelerometer families for structural monitoring. The IEPE technology is ideal for smaller structures where higher frequencies are being focused on. While the MEMS capacitive technology is best used for larger structures which experience DC or low frequency signals.

In the first part of this paper, we will detail the technical specificity of MEMS Capacitive technologies. Some application oriented technical considerations will be made such as driving long cables, EMC protection and thermal stability. In the second part of this paper, three applications will be described where Kistler MEMS Capacitive Technologies have been used for Modal Investigation and Structural Monitoring. Details on sensor selection, implementation and signal computing relevant to those applications will be provided.