冰载荷激励下内河船推进轴系扭转振动研究

Research on Torsional Vibration of Inland Waterway Vessel Propulsion Shafting Under Ice Load

以一艘内河实船推进轴系为例,利用场矩阵法与霍尔兹表法研究系统自由扭振固有频率,根据1阶及2阶固有频率下的共振转速通过放大系数法及场矩阵法对比研究柴油机稳态激励下系统强制扭振,分析两种方法的频域结果.利用Newmark积分及编程计算求解冰载荷下轴系扭转应力的时域响应,对比分析冰载荷下轴系瞬时扭转应力与柴油机激励下的稳态扭转应力.结果表明:冰块撞击后轴系扭转应力超过许用应力值并远大于无冰块撞击时的扭转应力.

Taking the propulsion shafting of a real inland ship as an example,the natural frequency of free torsional vibration of the system was studied by using field matrix method and Holtz table method.According to the resonance speed at the first and second natural frequencies,the forced torsional vibration of diesel engine under steady-state excitation was comparatively studied by amplification coefficient method and field matrix method,and the frequency domain results of the two methods were analyzed.Newmark integral and programming calculation were used to solve the time-domain response of shafting torsional stress under ice load,and the instantaneous torsional stress of shafting under ice load and the steady torsional stress excited by diesel engine were compared and analyzed.The results show that the torsional stress of shafting after ice impact exceeds the allowable stress and is much greater than that without ice impact.