([[Secondary articles descriptions#Passive Constrained Layer Damping, SotA|source]])

*Passive Constrained Layer Damping*

[[Viscoelasticity|Viscoelastic materials (VEM)]] dissipate energy under a transient deformation. Used in a form of a layer that is either freely attached (UCLD ie *unconstrained layer damping*) or in a sandwich (CLD/PCLD ie *constrained layer damping/passive constrained layer damping*).

In most of the analyses, extensional/compressional strains of the viscoelastic layer are not taken into account since the damping comes mostly from the shear strain. However, with a thick layer, compressional damping cannot be neglected.

The mathematical models are either [[Finite element method|FE]] or analytical.