To achieve high-performance aircraft structures, new tailored and cost-effective materials are continuously designed and tested. Nowadays Fibre Metal Laminate (FML) technology is optimised for fatigue and damage tolerance properties, which is one of the reasons for its application in the upper shells of the A380 aircraft fuselage. Fatigue crack propagation in FML is a subject of great interest which has only recently reached a well defined theory and validated modelling tools are required.
This study investigated using numerical and experimental techniques to characterize the static and fatigue strength of a flat stiffened panel, designed as a Fibre Metal Laminate (FML) and made of aluminium alloy and Fibre Glass FRP. The full scale panel was tested under both static and fatigue bi-axial loads, applied by means of an in house designed and built multiaxial fatigue machine. The strain gauge outcomes from a preliminary static test were compared with the corresponding numerical results, achieving a satisfactory correlation. Crack propagation in the FML was also simulated.
To overcome the lack of experimental information on the size of the delamination area an ‘‘inverse’’ procedure was applied to minimise the numerical and experimental growth rate differences.
This approach provided a general purpose evaluation tool for a better understanding of the fatigue resistance of FML panels, providing a deeper insight into the role of fibre stiffness and of delamination extension on the Stress Intensity Factors.