Application of rotation rate sensors in measuring beam flexure and structural health monitoring

Abstract

This paper presents a new approach to measure and monitor structural vibrations in civil and seismic engineering which uses new rotational sensors which can measure flexural vibrations of a beam axis. First a rotation rate sensor (measuring rotational velocity) is tested with respect to its ability to follow changes of strains in a beam during its vibrations. Next a system of rotation rate sensors is applied to effectively reconstruct stiffness variations of a simple, cantilever beam. It is demonstrated that the rotation rate sensors can be used to effectively reconstruct three unknown stiffness drops of a cantilever beam under harmonic vibrations. Both experiments are carried out using small plexi beams in laboratory scale. At this moment the rotational sensors are still rather expensive and with limited range and accuracy. However with the time passing by, their quality will improve and prices decrease making them very effective instruments in seismic engineering and health monitoring of structural systems.