are more versatile for design and system validation purposes and can produce simulation data that can readily compared to published industry standards. These codes make it easy to add system branches, mass-elastic data, steady-state loads, transient disturbances and many other items only a rotordynamicist would need. Torsional vibration specific codes: AxSTREAM RotorDynamics, ( SoftInWay) - Commercial FEA-based program for performing the full scope of torsional analyses on the complete range of rotating equipment. Can be used to perform steady-state and transient, modal, harmonic and reciprocating machines analysis, and generates stability plot and Campbell diagrams quickly. ARMD TORSION (Rotor Bearing Technology & Software, Inc.) - Commercial FEA-based software for performing damped and undamped torsional natural frequencies, mode shapes, steady-state and time-transient response of mechanical drive trains with inputs of various types of external excitation, synchronous motor start-up torque, compressor torques, and electrical system disturbances. Bond Graphs can be used to analyse torsional vibrations in generator sets, such as those used aboard ships. See also Torsion (mechanics) Torsion coefficient Torsion spring or -bar Torque Damping torque Bibliography Nestorides, E.J., BICERA: A Handbook on Torsional Vibration, University Press, 1958, References External links Torsional Vibration Application Case for Vehicle Frontend Accessory Drive Mechanical vibrations