7. Conclusion

Since composites are highly sensitive to impact, impact damage tolerance is a highly dimensional case for aeronautical composite structures. The complexity of this design case stems from the fact that we have to consider both the impact damage, or more precisely the drop in residual strength due to this impact, and the detectability of this impact, or more precisely the permanent indentation left by this impact.

In order to justify the impact damage tolerance of a composite structure, the first step is to determine the curves for residual strength and permanent indentation as a function of impact energy, and then, given the limit loads (CL) and extreme loads (EL), to show that the conditions for impact damage tolerance have been met. In particular, the aim is to show that for undetectable damage, the structure can withstand the EC, and that for detectable damage,...