Strain sensing of beams in flexural vibrations using rotation rate sensors

Abstract

This study investigated the application of rotation rate sensors to measure flexural vibrations of beams. This new area of the application of rotational sensors can be beneficial for monitoring various structures, particularly civil engineering structures like reinforced concrete beams and frames and masonry structures, which are difficult to assess using vibration-based damage detection techniques. In a small-scale laboratory experiment, Horizon HZ1-100-100 rotation rate sensors were put in the middle of a plexiglass cantilever beam along with four strain gauges. The beam underwent kinematic excitations, during which variations of the rotations and strains are observed simultaneously. Results of the tests are presented in detail and it was concluded that the rotation rate sensors can be effectively used to monitor flexural vibrations of beams, with particular attention to indirect strain monitoring. In addition, a simple test to check the effectiveness of the rotation rate sensors to monitor stiffness drops in localized locations was carried out. The experiments demonstrated that rotation rate sensors have potential to dramatically improve SHM of civil engineering structures and with improved accuracy, these sensors can find wide application in on-line and post-earthquake structural assessment.