Torsional vibrations lead to oscillations in the electromagnetic torque, too. These may dampen the vibrations, but they may also do the exact opposite.
Of mechanics in electrical machines, torsional vibrations are often the most critical. Read here to learn the basic principles, and how to analyze them.
Vibrations in electrical machines can be divided into several categories, differing on the mechanism and type of vibrations produced.
The magnetic forces in an electrical machine deform it, and the mechanical stresses influence the magnetics. Read more about this interaction here.