The role and effect of damping on the response of a flexible shaft in the region of a critical speed

An experimental study concerned with the role and effect of damping for a rotating flexible shaft in the region of a critical speed is conducted. The existing theory (1) is reviewed for a rotating system with an unbalanced disk in the center of a flexible shaft. The effect of damping on the system is discussed. The experimental results reveal that the external damping plays a role which is taken properly into account by the existing theory. In contract, internal damping does not affect the rotating system in the region of the critical speed.