Objectives  To clarify the torsional vibration calculation method for matching the medium-high speed diesel engine with the multi-elastic coupling, and to obtain the torsional vibration characteristics,

  Methods  taking a MTU diesel engine propulsion shaft system as the study object, the matching method of multi-elastic coupling was studied, and the calculation model of MTU diesel propulsion shaft torsional vibration was established. The excitation characteristics of MTU diesel engine and the torsional vibration characteristics of the propulsion shaft were analyzed. The prediction of torsional vibration characteristics of MTU diesel engine and multi-elastic coupling matching series was carried out. Based on the measured amplitude, the damping correction calculation method based on analytical method was proposed to correct the prediction results of torsional vibration characteristics of shaft system.

  Results  This research shows that measured resonant frequency matches the calculated frequency, after correction, the crankshaft stress at the resonant speed is reduced by 16%, and the vibration torque of the elastic coupling is reduced by 15%. The correctness of the torsional vibration calculation method is verified.

  Conclusions  The results of this research can provide engineering reference for the torsional vibration analysis of the same type of warship.