Use of Viscoelastic Laminae: Additive Layer Damping using VEM

Layers of Viscoelastic Materials are used often for vibration control. These are of two types:

• unconstrained
• constrained.

For unconstrained damping, the V.E. layer is placed over one of the surfaces as shown in Fig 15.1(a)

Figure 15.1

Here, the vibrational energy is dissipated due to the extensional deformation of the high damping viscoelastic layer. For constrained layer damping (also known as CLD or PCLD) , the damping layer is sandwiched between the vibrating surface and a stiff constraining layer (Fig. 15.1 b). In this treatment, most of the energy is dissipated due to the shear deformation of the viscoelastic layer.