DynamicanalysisofrotatingmachineryhascomealongwaysinceProfessorStephenTimoshenkoconsideredthecaseofauniformshaftwithadiskateachendinhisfirsttechnicalpaper“OYavleniyakhRezonansavValakh(OnResonancePhenomenainShafts)”intheBulletinofthePolytechnicalInstituteofSt.Petersburg.Modernturbo