Quantifying local stiffness loss in beams using rotation rate sensors

摘要

The application of rotation rate sensors in vibration-based damage detection is investigated. For this purpose, simulation, FEM analyses of a damaged cantilever plexiglass beam under kinematic excitations are carried out and verified experimentally. Three types of rotation rate sensors are examined. Damage index based on the maximum difference of signals on both sides of the damaged location is compared with averaged damage indices in time and frequency domain. It is demonstrated that the rotation velocities of the beam axis are less sensitive to measurement noise than the transversal accelerations. A simple damage index based on peak response and two, integral damage indices were tested using numerical simulations and laboratory experiments. The integral time-domain damage index appeared to be equally useful in damage detection, like the index based on the trans-missibility concept. The results of the experiments show positive prospects for constructing Structural Health Monitoring (SHM) networks using rotation rate sensors. This is particularly important for future SHM systems to be commonly implemented in civil engineering.