船舶推进轴系振动的不确定性分析

Uncertainty analysis of propulsion shafting vibration

  • 摘要:
      目的  针对传统的船舶推进轴系确定性振动分析存在安全性与可靠性不足的问题,开展轴系在不确定性激励下的振动响应分析。
      方法  采用基于非概率凸模型过程的非随机振动分析方法,以区间上下界的形式描述不确定性激励和振动响应,降低对大量激励样本数据的依赖。与相关文献的计算结果对比,验证所编求解二自由度系统响应边界程序的正确性,并基于在此,探究轴系的不确定振动问题。
      结果  当轴系受到螺旋桨−30 N,30 N的横向激励力激励时,在轴承处产生了量级约为10−6 m的位移响应,表明轴系受到某一区间的激励,则必会产生某一区间的响应。
      结论  将基于非概率凸模型过程的非随机振动分析方法应用于船舶推进轴系不确定性振动分析领域,可求得轴系受到不确定性激励时的振动位移响应边界,并可在激励样本较少的情况下为提高轴系系统动态响应预测的稳健性提供有益参考。

     

    Abstract:
      Objective  In view of the insufficient safety and reliability of the traditional deterministic vibration analysis of ship propulsion shafting system, the vibration response analysis of the shafting system under uncertain excitation conditions is carried out.
      Methods  Using non-random vibration analysis based on non-probabilistic convex model process, the uncertain excitation and vibration response are described in the form of the upper and lower bounds of the interval to reduce dependence on a large amount of excitation sample data. Compared with the calculation results in the relevant literature, the validity of the program for solving the response bound of the two-degrees-of-freedom (2-DOFs) system is verified, and the uncertain vibration problem of the shafting system is then explored on this basis.
      Results  The results show that when the shafting system is excited by −30 N, 30 N propeller laterally, a displacement response of the magnitude of about 10−6 m is generated at the bearing. It is also indicate that the shafting system is excited in a certain interval, so a certain interval response must be produced.
      Conclusions  Applying the non-probabilistic convex model process and non-random vibration analysis to the field of the uncertain vibration analysis of ship propulsion shafting system, the vibration displacement response bound of the shafting under uncertain excitation conditions can be obtained with fewer excitation samples, thereby providing useful references for improving the robustness of the dynamic response prediction of ship propulsion shafting systems.

     

/

返回文章
返回