极地冰区船舶推进轴系共振方法的应用

Application of Resonance Method for Ship Propulsion Shafting in Polar Ice Regions

船舶在冰区航行时,推进轴系产生共振现象比在非冰区航行产生共振现象的几率大很多,这是因为冰块对螺旋桨的瞬时载荷非常大,如果轴系设计不当,很容易产生轴系共振现象。轴系振动一般情况分为扭转振动、回旋振动、纵向振动和相互耦合振动。采用有限元仿真计算得到的几种评估冰区船舶推进轴系振动是否共振的方法:通过计算轴系的扭转振动频率、扭矩、扭转应力和放大系数,查看轴系扭转振动是否达到共振现象;通过计算轴系回旋振动频率,查看轴系回旋振动是否达到共振现象;通过计算轴系纵向振动的频率和振幅,查看轴系纵向振动是否达到共振现象。在轴系设计过程中,可以对其进行振动的仿真计算,能有效地、预见性地避免轴系共振。

The probability of resonance phenomenon in the propulsion shaft system of ships sailing in ice areas is much higher than that in no-ice areas.This is because the instantaneous load of ice on the propeller is very large.If the shaft system is not designed properly,it is easy to produce shaft resonance phenomenon.The shaft system vibration is generally divided into torsional vibration,whirling vibration,axial vibration,and coupled vibration.Several methods for evaluating the resonance of the propulsion shaft system vibration of ships in ice regions using finite element simulation calculations:first,check whether the torsional vibration of the shaft system reaches resonance phenomenon by calculating the torsional vibration frequency,torque,torsional stress and amplification factor;Second,check whether the whirling vibration of the shaft system has reached resonance phenomenon by calculating the whirling vibration frequency of the shaft system;Last,check whether the axial vibration of the shaft system has reached resonance phenomenon by calculating the frequency and amplitude of the longitudinal vibration of the shaft system.