3. Conclusion

Traditionally used for their high specific mechanical properties, rigidity and strength, composite materials also possess damping properties, which are more or less pronounced depending on the nature of the material and the direction considered. These damping properties must be taken into account in the vibratory behavior of composite structures, as they have a strong influence on their resonance acuity.

The behavior of organic matrix composites is similar to that of polymers, with frequency-dependent stiffness and damping. The measurement difficulties are similar: no single instrument can cover a wide range of frequencies (several decades), and the accuracy of stiffness measurements is far greater than that of damping. The anisotropy of the composite material is a further source of difficulty, since it requires multiple dynamic tests with perfect control of the...