Due to the problems arising from impact damage in composite laminates, there is a need to develop fast,\udaccurate, cost-effective and non-destructive testing methods to identify this type of damage at an early\udstage and thus enhance the service life of composite structures. This paper presents the results of an\udextensive experimental campaign conducted to investigate the feasibility of using vibration-based methods\udto identify damages sustained by composite laminates due to low-velocity impacts. The experimental\udprogramme included an evaluation of impact damage resistance and tolerance according to ASTM test\udmethods, characterisation of induced damage by ultrasonic testing and quantification of the effects on\udthe vibration response. The damage identification involved the detection, localisation, quantification\udand estimation of the remaining bearing capacity. Four damage indicators based on modal parameters\udwere assessed by comparing pristine and damaged states. The results allowed for conclusions to be\uddrawn regarding the capability and suitability of each damage indicator, including its ability to detect\udimpact-induced damage, its precision in determining the location of damage, its sensitivity regarding\uddamage extent and pertinent correlations with residual bearing capacity.
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