Dampening is a process whereby mechanical energy is converted to thermal energy. Materials or systems under cyclic stress have a damping ability which is an energy dissipation property. The energy that is dissipated is used to measure the material damping level.
Vibration damping materials have been used in industries, electronics and in various structural and ergonomic applications to reduce production of noise.
Vibration damping materials change a material’s natural vibrating frequency which results ina decrease in radiated noise and an increase in the transmission loss of the material. Vibration results from internal and external forces. The effects of vibration vary from one application to another. In some instances, vibration dampening is utilized to achieve a more pleasant experience as achieved by a reduction in noise or movement from a system. However, in many large scale industrial applications, vibration dampening is necessary to allow the machinery to successfully and safely operate.
Computers, mobile phones, navigation systems of cars and other electronics are all prone to internal and external sources of vibration. The sources of vibration can even be caused during shipping or by dropping the productaccidentally. Vibrations can result in damage to electronics, hence it’s of great importance to consider vibration damping for electronic devices. Such damages can include weakening of computer connections, data loss, disk drive destruction and reduced efficiency and function of the electronics.
Great care has to be taken in choosing a proper damping material as a result of the rise in the use of electronic devices such as mobile phones, tablets and laptops. Such devices are both expensive and are subject to near constant use, therefore care should be observed in choosing an ideal vibration damping material to absorb the shock and reduce the damage risk that could be caused from impact.
Thin metals parts easily transmit noises upon impact or through excitation by acoustic energy. Metals are a problem in various applications due to their vibration properties. This problem can be solved by using an appropriate vibration damping material.
Common vibration damping mechanisms
The most common mechanisms that are used to address vibration issues include: viscoelastic damping and Sorbothane.
Viscoelastic damping is the most common mechanism that is used to address the problem of vibration. Viscoelastic means that the material exhibits both the viscous properties of liquids and elastic properties of solids. An elastic material stores all its energy when loaded and releases this energy when the loading material is released. A viscous material does not release energy by removing the loading material, but instead all the energy is lost via “pure damping” by removing the loading material. In viscoelastic damping mechanisms, the viscous material stores some energy while some is lost in the form of heat.
Sorbothane damping mechanism is whereby the damping material has viscoelastic vibration damping properties and also incorporates the following properties that include shock absorption properties, good memory, vibration isolation and vibration damping. All of this properties are incorporated into one material. Sorbothane is thus a widely used and very efficient acoustic damper and absorber.