Aimed at solving the problem of large-area detection for aerospace laminated structures with curved surfaces

laser ultrasonic technique with non-contact measurement has attracted more and more attention. By using pulsed laser to generate the ultrasonic waves in the structures

the wave-field data can be obtained. Through analyzing the characteristics of ultrasonic wave propagation

the structural damage detection and mechanical property identification can be achieved. Focused on the widely used aerospace composite structures

this paper presents the research progress on three aspects: debonding damage detection

damage accumulation characterization and fatigue life prediction. Taking laminated composite structures as an example

the influence of debonding damage on ultrasonic wave propagation is studied. By extracting the damage index

such as wave energy and wave number

the debonding damage can be visualized. Then

the influence of matrix crack accumulation in fiber reinforced polymer on mode conversion is investigated. By defining a mode-to-mode ratio

the density of matrix cracks can be characterized. Finally

a micro-damage based fatigue evolvement model for composites is established. Through Bayesian model averaging and wave velocity measurement using laser ultrasonic technique

the fatigue life of composites can be predicted

providing foundation for non-destructive testing in aerospace composite structures.