Optimisation-based damage assessment of laminated composite beams using vibration data

The increasing application of laminated composite beams as structural load-bearing elements necessitates the understanding of the complex damage mechanisms of such materials and the development of reliable and easy-to-apply methods for timely damage detection. The use of damage detection methods based on vibration data together with robust computational algorithms in such materials appears to be a very good option due to its ease of application. Recent research in this field has accelerated and garnered significant industrial and scientific interest worldwide. However, the practical application of optimization methods in vibration-based damage detection for composites remains limited. This thesis proposes an effective method for solving the damage detection problem in laminated composite beams through optimization-based finite element model updating. A finite element model with thirteen degrees of freedom was developed for numerical modelling, capable of accounting for the Poisson effect as well as extension-bending, bending-torsion, and extension-torsion couplings. Damage was defined as a reduction in stiffness in the model. Three different objective functions based on vibration characteristics were used in the solution. The numerical and experimental validation of the method was conducted on composite beams with various damage scenarios, different boundary conditions, and layer configurations, and its effectiveness was evaluated.