Experimental investigation of the periodic core sandwich structure: Shape of the vibration modes
Résumé
The sandwich structure allows to shearing the viscoelastic core layer and increase passive damping. This paper focuses on an investigation of the modal behavior of the sandwich structures with homogeneous cores and periodic cores. Two polymers are selected for their adhesion properties to metal surfaces and their viscoelastic properties. A numerical approach is presented to solve the vibration problem and determine the response curve. Periodic sandwich beams are elaborated with two viscoelastic polymers which are chosen for these characteristics. Scanning vibration allows the measurement of the deflection shapes of the fourth mode. The deflection shapes in the case of a periodic core sandwich show discontinuities localized at the interfaces of the periodic structures. These irregularities in the deflection shapes can be predicted and localized by our numerical model. The results show the importance of considering the impact of the modal behavior using a periodic core sandwich.