(iv) Use of Additive Layers

This involves addition of a secondary vibratory system to the original (primary) vibratory system which is under excitation. Some secondary systems are vibration neutralizer, vibration absorber, tuned, self-tuned, impact absorbers. This strategy has been successfully used for suppressing vibration in very small to very large systems.

Examples: electric hair clippers, DC-9 aircraft, tractors, foot bridges, pipelines etc.

Viscoelastic materials are used as additive damping treatments: constrained and unconstrained layers

Extensional and shear deformation of the damping layer

Often spacers are designed to enhance extensional damping