Viscoelastic damping design – Thermal impact on a constrained layer damping treatment

Constrained layer damping treatments have been commonly used for vibration damping. The included viscoelastic material exhibits high damping potential that is retrieved under shear deformation. However, the impact of temperature on the viscoelastic properties and thus on the vibration damping often remains unconsidered. This paper addresses the design of viscoelastic damping under thermal consideration. For this purpose, the frequency and temperature dependent properties of a bromobutyl rubber compound were characterized in a dynamic mechanic thermal analysis. The viscoelastic material properties are employed in a finite element model of a structure with a constrained layer damping treatment. Subsequently, the modal damping of the structural vibrations is analyzed under varying temperature conditions. The analyses show a significant thermal impact on the modal damping. In this context, an approach is presented for compensating the adverse thermal effect on damping by a modified geometric design of the viscoelastic core layer.