轴承刚度对船舶推进轴系振动传递路径影响分析

采用传递矩阵法,将船舶推进轴系简化为质量点单元、弹性支承单元和具有分布参数的梁单元。基于修正的Timoshenko梁理论,推导出推进轴系的场传递矩阵表达式。然后,引入相应的边界条件,形成方程组并实现不同轴承刚度下推进轴系轴承处的力和位移响应求解。最后,从能量的角度,对推进轴系各轴承传递路径处的功率流进行分析,并与有限元结果比较。结果表明:基于修正Timoshenko梁理论的传递矩阵法在计算推进轴系弯曲振动时是可行有效的;艉后轴承刚度对轴系振动传递影响最大,艉前轴承次之,推力轴承影响最小。

Analysis of the Effects of Bearing Stiffness on Vibration Transmission Paths in Ship Propulsion Shafting

The ship propulsion shafting is simplified to quality point unit, elastic supporting element and beam elements with the distributed parameters and the expression of field transfer matrix of the ship propulsion shafting is deduced by the transfer matrix method based on the modified Timoshenko beam theory. Then, the solution of the bearing force and the displacement response of the propulsion shafting is carried out by introducing the corresponding boundary conditions. Finally, the power flow of each bearing of the propulsion shafting is analyzed numerically from the perspective of energy and compared with the result by FEA approach. The analysis results show that it is feasible and effective to calculate the propulsion shafting bending vibration by the transfer matrix method based on modified Timoshenko beam theory; the aft stern bearing stiffness has the biggest influence on transmission path, followed by the front stern bearing and the minimal one, the thrust bearing.