Endurance tests performed using contact and contactless excitation methods: Application to composites components

Understanding composites behaviour under resonant loading conditions is sometimes a challenging area of research; one of the reasons lies on the ability of testing composites to endurance life. If on one hand the behaviour at static loading is being studied and understood in depth using reliable testing methods, the dynamic aspect is still poorly known. Composite materials have got a higher level of structural damping than the metallic ones. Further to this, the damping behaviour can change during endurance trials and thus becoming non-linear. Their non-linear behaviour and their high damping, related to each resonance frequency, requires the implementation of new test methods which may be able to overcome issues such as mechanical impedance, coupling, insufficient strain energy produced. This work will present two testing methods developed for performing endurance of composites components.