Proper orthogonal decomposition based algorithm for detecting damage location and severity in composite beams

A damage detection algorithm based on the proper orthogonal decomposition technique that can be used for structural health monitoring is presented in this study. The proper orthogonal modes are employed as dynamical invariants to filter out the influence of operational/environmental variation in the dynamic response of the structure. Finite element models of a healthy and damaged carbon/epoxy composite beam are used to generate vibration data. Varying levels of stiffness reduction for the elements in the damaged zone of the structure are used to simulate impact damage. Three damage locations (center of beam, fixed end, and free end) with three damage cases for each location are investigated. Different random force inputs are used to introduce variations in the loading conditions of the beam. The results show that the developed algorithm is capable of detecting both location and severity of damage even under changing loading conditions, with a high level of confidence.