A novel damage detection technique for laminated composite beams under the action of a moving load

The present paper investigates damage detection in laminated composite beams under the action of a moving load. A novel approach is introduced to present damage indices by utilizing the dynamic response of the beam. The equations of motion for the beam have been derived by considering in-plane and out-of-plane deformations, rotary inertia, and shear effects. To obtain the solution, the finite element method, in conjunction with the Newmark algorithm, has been employed. Three damage indices, namely the Displacement Variation Index (DVI), Velocity Variation Index (VVI), and Acceleration Variation Index (AVI) have been introduced. These indices are utilized to detect the location of damage based on the beam's displacement, velocity, and acceleration, respectively. Furthermore, the proposed approach enables to detect single and multiple damages at different severities, locations, and boundary conditions. Likewise, it is applicable to various velocities of moving forces and can effectively operate in both normal and noisy conditions. The results of this investigation demonstrate that the proposed damage indices are able to accurately detect damage along the entire length of the beam without prior knowledge of its healthy state. It is noteworthy that the acceleration-based index, among the indices pro-posed in this study, exhibits the highest efficiency in determining the precise location of the damage under operational conditions.