ABSTRACT
Transport by sea gets increasing in Arctic and Antarctic region as climate change progresses. The latest polar class ship rules from the International Association of Classification Societies (IACS) require torsional vibration simulation of ice block impacts on ship’s propeller blades. In general, excitation from ice load is considered as transient shock. The simulation should be calculated by the time domain torsional vibration, where transient load is applied. The key techniques and influencing factors such as modeling method, calculation method, excitation, damping, speed drop correction and electric motor characteristic in the calculation of transient torsional vibration on motor propulsion shafting are studied. And the general process of transient torsional vibration calculation for electric motor propulsion shafting under ice load is established. The Newmark-β step-by-step integration method and the MATLAB tool are used to simulate the transient torsional vibration of the ship′s propulsion shafting. The steady-state calculation in the time domain shows acceptable agreement with the frequency domain result. The calculation software is developed and validated by motor propulsion example. The research can provide engineering reference for transient torsional vibration calculation due to ice impact on electric motor propulsion shafting.
