Damping systems for vibrating members

A method of damping a vibrating member comprising the steps of:

• providing the vibrating member, the member having a cavity;
• filling the cavity with the low-density granular material having a sound speed of 90 meters per second or less providing relative movement between the member and fluid such that the low-density granular material damps vibration of the member during rotation of the member.

A vibration damped rotating system comprising:

• a rotating member having a cavity;
• a low-density granular material having a specific gravity less than 0.6 and being positioned within the cavity to damp vibrations of the rotating member.

A vibration damped system that is subjected to an external force comprising:

• a first rotating member undergoing vibrations from the external force the first member having a quantity of low density granular material to damp the vibrations;
• and
• a second member coupled to the first member, the second member having a quantity of low-density granular material coupled to the second member to damp vibrations of the second member, the low density granular material having a sound speed of less than 90 meters per second.