Study On The Structural Vibration And Cabin Noise Control Technique Of Full-turning Tug

The power equipments of full-turning tug are many and the power is large, so thecabin vibration and noise of full-turning tug is prominent, this problem influences thelives and working environment of crew. The research in the control of full-turning tugvibration and noise is less at present, this paper takes a36m full-turning tug as theresearch object, based on FEA and SEA, researches the full-turning tug vibration,noise and control systematically by numerical simulation method, at the same timeadopts the method of experimental measurement, verified the accuracy and feasibilityof the numerical simulation.First the noise and vibration sources of ship were expounded, the noise andvibration sources of full-turning tug were analyzed, the air and structure noise thatengine, generator set and propeller made were analyzed intensively, and the spectrumsof them were gotten through empirical formula and experiment.To research the vibration transfer ratio of full-turning tug, the part-cabin modelwas made, and the gravity hammer experiment was done through the Brüel&Kj rhammer and four channel signal acquisition instrument, in the different frequencybands, the difference of equivalent transfer functions of the measure points weredifferent, this phenomenon was focused in40~630Hz.Secondly the theory of FEA was introduced, the superelement model of36mfull-turning tug was esTab. lished though MSC.Patran, then the modal analysis andvibration prediction were done, at the same time the vibration data from the same typetug was gotten by the MVP-2C, then the vibration data was compared with thesimulation results to verify the accuracy of the model.The theory of SEA was introduced, based on the FEA model, the SEA model of36m full-turning tug was esTab. lished through VA One, and the energy propagationpath was analyzed, the cabin noise prediction was done, at the same time the vibrationdata from the same type tug was gotten by the Brüel&Kj r2250, then the noise datawas compared with the simulation results to verify the accuracy of the model, and the noise contribution of the noise sources were analyzed.At last same noise and vibration reduction methods were introduced at present,and the theories were expounded, according to the actual situation, the engine wasisolated based single isolation, the vibration isolation effect is close to5dB, and thenoise reduction effect is close to6dB(A), at the same time, the cabins were disposedby pasting the sound-absorbing material to reduce the cabin noise, the noise reductioneffect is obvious, about4.7~7.2dB(A), when the single isolation and sound-absorbingmaterial pasting were adopted at the same time, the noise reduction effect is the mostobvious, about11dB(A).