Coupled Vibration Attenuation Between Beam-Shafts Based On Wave Approach

Ship shafting and pipeline system are important parts of the ship power system,both are the same as beam elements,with similar physical structure and vibration characteristics.Shafts and pipelines are widely distributed in the ship with complex usage situation.Their safety,reliability and stability directly affect the running condition of the ship,so the vibration attenuation between ship beam-shafts has always been the focus of scholars.With the development of modern ship,the vibration of ship beam-shafts has been more complicated,and the vibration and noise reduction task has been more difficult,which brought severe challenges to the safety of the ship and the staff.Therefore,the coupled vibration attenuation between ship beamshafts structure is put out in this paper,which aims to explore the transmission rules of vibration and noise control measures between the ship beam-shaft structure,and to provide a reference for the acoustic design of beam-shaft structure.In this paper,the similarities and differences between shaft and pipeline vibration are indicated in three aspects,theory studies,numerical calculation and experimental research.Firstly,the system is simplified to two semi-infinite long beams.Vibration energy transmission of two semi-infinite long beams is indicated by wave approach,based on Euler-Bernoulli beam theory.Through numerical analysis,the parameter change on the vibration energy transfer is obtained,under the bending wave incidence.Then according to the difference of shafting and pipeline structure,the finite long beam structure is established.The whirling vibration of shafting and pipeline structure with pipe support is analyzed and calculated to explore its natural frequency.Finally experimental bench is set up,based on the theoretical analysis.By comparing measurement and simulation results in typical conditions,the prediction reference of pipeline layout is summed up.Theorical calculation and experimental measurement is combined in this paper.In the theory aspect,wave approach is used to solve the stress balance equation.And several non-dimensional coefficients are introduced not only to simplify the equations,reveal relevant physical sense,but also to facilitate similarity experiment with small models for investigations on structural vibration in large practical engineering structure.In the experiment aspect,a variety of pipe structure model is measured in various conditions.The experimental results and theoretical calculation results are basically consistent,which shows the availability of this study.In summary,in this paper,the vibration attenuation of ship beam-shafting structure is revealed with a new theorical calculation method,which provides a reference for ship beam-shaft structure design and layout.By changing structural parameters,the vibration and noise can be reduced in the ship machine.