The objective of this master project is to improve the current SHM techniques for global damage identification of beam-like composite structures. The studied damage diagnosis method is based on structural vibrations from which the modal parameters are obtained. The literature study provides an overview of the most common vibration-based damage identification methods. The modal curvature shape- and modal strain energy-based methods are selected due to their higher sensitivity to local damages. These methods are applied on an aero-elastically tailored composite wing. High-spatial-resolution modal shapes are extracted from the structure with a state-of-the-art fibre optic strain sensing technology based on Rayleigh back-scattering. Damages are simulated in the wing employing localized mass attachments. The achievable level of damage identification with this technique is found and characterized. The different vibration-based methods are compared and their potential is discussed. It is concluded that the used sensing technique is an excellent choice for global damage diagnosis in composite structures.