This option allows you to input the modal damping factors, if the direct damping is not available. In general, the torsional damping for a geared train system is not readily available from the element level. The torsional modal damping factors for systems with dry type couplings have been reported in the range of 1-5 percent. For systems with resilient rubber couplings, the modal damping of the coupling modes, where the motions are dominated by the coupling, can go up to 6-10 percent. For practical purpose, only the first several modes are of interest, modal truncation is employed to approximate the physical damping. The modal damping factor is the ratio of the actual modal damping to the critical modal damping for a given mode. If the modal damping factor is equal to and greater than one (1), the associated mode is said to be critically damped. Typical value is between 0.01 (1 percent) to 0.1 (10 percent). The definition of modal damping factor is:
See other Torsional/Axial Data Torsional/Axial Data.
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