Study On The Global Vibration Of Steel Refrigerated Transport Fishery Ship

In recent years,the aquaculture industry has gradually developed to the ocean,and the requirements for fishery transport vessels have been gradually improved.Some ships on the ocean have to face a lot of problems which have not encountered.This paper deals with the problem of excessive vibration of hull in the operation of a fishing vessel in the North Pacific Sea,and studies the overall vibration of the fishery carrier.Firstly,it introduce the theory of total vibration and local vibration of the ship,and the calculation method of the natural frequency of the ship's total vibration is also introduced.Some of the empirical formulas can also be used to calculate the natural frequency,although there are some problems.Then the formula of the local vibration of the ship and the problems needing attention in the calculation are introduced.Secondly,as the ship in the wave behave excessive vibration,the writer determine the real sea test program.The ship in the real sea test,respectively,on the right side of the ship rear mast,the ship front right mast,superstructure front wall,mast,bow Decks and other locations for real sea vibration measurement.Then the measured results were analyzed,combined with the vibration comfort level,getting the area vibration exceeded and the reasons for excessive vibration.Thirdly,the whole structure and local structure of the ship are modeled by the finite element analysis software MSC.PATRAN / NASTRAN,and the quality model and the attached water quality are applied to the model.The analysis model of the ship vibration is established.State analysis,combined with real sea test data,to further analyze the reasons for the overall vibration of the ship.Finally,after obtaining the reasons for the excessive vibration of the ship,a number of modifications to the ship were proposed.The finite element analysis software MSC.PATRAN / NASTRAN is used to calculate these transformation schemes,and then the data are analyzed and the final improvement scheme is determined according to the vibration comfort degree.