Vibration Sensor Placement for Delamination Detection in a Beam Structure based on the Vibration-based Chaotic Oscillator Method

This work aims to study the vibration sensor placement for detecting delamination damage in a beam structure using the vibration-based chaotic oscillator method. Although the existence of delamination in a beam structure influences its vibration characteristics, it can be difficult to detect by vibration measurement particularly when the measured vibration signal was corrupted by considerable measurement noise. Thus in this work, a chaotic oscillator method was used due to its sensitivity to relatively small changes in measured vibration signal and robustness to measurement noise. The effect of vibration sensor placement to the delamination detection sensitivity for various delamination sizes and locations was investigated. The Lyapunov Exponent was used in conjunction with the chaotic oscillator as a damage index, a measure to describe the extent of delamination damage in the laminated beam. The correlation between the damage index and sensor placement for different delamination properties was investigated to determine the optimal sensor placement. It was found that a sensor placed in the optimized region can provide sufficient sensitivity in detecting a particular vibration mode under different delamination sizes and locations. The results from this work demonstrate the effectiveness of the proposed method to determine the optimal placement for vibration sensors.