The vibration propagation in the damped structure is much lower then in the undamped one. The is due to the viscoelastic effects in the damping material. The dynamic deformations in the viscoelastic material, due to the vibration, consume the vibration energy and transforms it into a different form of energy e.g. heat. This loss of energy will therefore reduce the vibration level.

In order to prevent that noise is transmitted between two rooms or cavities, reflecting/insulating barriers can be used. The barrier need sufficient weight, but unfortunately it is a bit more complicated than that. The barrier also needs to be damped in order to prevent a low reduction of the noise transmitted above the coincidence frequency. Double wall constructions are often used to obtain a cost effective solution.


Insulation solutions can also be used to reduce vibrations, for example on a floor. In this case a decoupling material is place between the base construction and a damped top surface material, for example damped steel sheet. These solutions are normally called “floating floors”.

FMT acoustics has the capabilities to simulate and calculate the loss factor and transmission loss for different applications.

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  PUD 20 Two component polyurethane compounds to be used in constrained layer application. To be used on floors together with sheet metal or concrete.
  PUD 30 Two component polyurethane compounds to be used in constrained layer application. To be used on walls and sloping floors together with sheet metal.
  DLV 1000 One component acrylic compound optimized to give a high composite damping, constraining layer application.
  DLV 2000 One component damping glue DLV 2000 is a viscoelastic glue optimized to be used in wood constructions.
  NGN 2000 Viscoelastic sheet with very high damping, designed for constrained layer damping of fibreglass reinforced plastic, wood or fibreglass / foam.
  DLM Damped laminated metal for: floating floors in ships, yacht, oil platforms, trains and busses. Double wall constructions and various machines.