DIN ISO 21940-12 Beiblatt 1:2015-04

Shaft-elastic behaviour of a rotor is when structural resonances are passed through or the operating speed of a structural resonance rate approaches to the extent that its effect on the rotor operation is no longer neglectable. By a systematic description of the unbalances by means of a modal view this supplement describes in detail the balancing at several speeds. For this purpose the following aspects are taken into account: - the unbalances to be taken into consideration, - modal unbalances, - flexural resonances to be taken into consideration, - tolerance specifications. This supplement compiles the findings with balancing procedure G according to DIN ISO 21940-12 to a practical recommendation for the design of the balancing process and closes the remaining gaps during the balancing of rotors with shaft-elastic behaviour. This supplement has been prepared by Committee NA 001-03-06-01 UA (NALS/VDI C 6.1) "Auswuchten und Auswuchtmaschinen" ("Balancing and balancing machines") of the Standards Committee Acoustics, Noise Control and Vibration Engineering (NALS) at DIN and VDI. It supplements DIN ISO 21940-12 "Mechanical vibration - Rotor balancing - Part 12: Procedures and tolerances for rotors with flexible behaviour" (currently draft).