Experimental Study And Numerical Simulation On The Vibration Characteristics Of The Ship Stern Structure

With the requirement of the high speed,the vibration problem of the ship is more and more serious.Compared to the parallel middle body,the stiffness of the stern structures is weaker.In addition,the stern is directly forced by the propellers.For these reasons,some harmful vibrations always exist in the region of the stern.At present,finite element numerical simulation is the main method to evaluate the vibration characteristic of the stern.However,the accuracy of the numerical simulation should be checked by the test data.Moreover,when refer to vibration transmission characteristic,the transfer function is used,but it can’t describe the specific transmission path.Therefore,in this paper,some research on the vibration characteristic of the stern are carried out both by experimental study and numerical simulation.Based on the test data,the accuracy of the numerical simulation is checked.Moreover,the vibration transmission characteristic is researched through the view of the power flow.The main research contents of this paper are listed in the following:(1)Structural design of the stern test model.The vibration characteristic of the original ship stern is analyzed.Try to find the vibration node of the single stern.The double scale is adopted to complete the design of the test model.(2)Mode and response analysis of the stern structure.Both experimental study and numerical simulation is carried out to analysis the vibration characteristic of the stern structure,the selection principles of the key parameters of the numerical simulation are checked by the test data.(3)Patran Command Language and Matlab are used to accomplish the visualization of the transmission path of the power flow.Based on the theory of the vibration power flow,the vibration transmission characteristic of the stern structure is carried out.The research on the effect of the change of structural form on vibration transmission characteristic is developed.In addition the effects of the different initial phase on the vibration transmission characteristic are carried out.The different damping coefficients of the dampers are connected to the deck to find the effect of the damper on vibration transmission characteristic.