| Large ship sailing on the Marine environment,used by a variety of external load,such as collision,explosion shock wave and the wave force,especially when the ship collision accident or by explosion shock wave,the action of impact load will cause the propulsion shafting-coupling vibration of the hull of the ship,or even cause a large deformation of the hull,affect the normal operation of the ship propulsion shafting,the propulsion shaft is the important power equipment of ships,it is directly affect the normal operation of the ship navigation safety.In this paper,a dynamic model of the coupling system of hull-oil film-propulsion shafting is established,and the dynamic characteristics of the coupling system of hull-oil film-propulsion shafting are studied by numerical simulation with MATLAB.At the same time in this paper,based on the model of 7000 DWT product oil ship,ship propulsion shafting model is established in the ANSYS environment and hull-propulsion shafting integration model,through the ANSYS simulation experiment research of ship propulsion shafting under explosion shock wave effect when the response of the shaft system,as well as the collision of the coupling vibration of hull-propulsion shafting and propulsion shafting dynamics influence.The main conclusions are as follows:1.The dynamic characteristics of the coupling system of hull-oil-film-propulsion shaft system were studied by numerical simulation with MATLAB.It was concluded that the vibration transfer of the ship shaft system was closely related to the structure state of the stern,and the main excitation frequency affecting the vibration of the stern shaft was low-frequency vibration.The stiffness of stern structure has an impact on the vibration characteristics of the coupling system.The reduction of stiffness leads to a rapid increase in the maximum amplitude of the stern shaft,and the lower the stiffness,the more obvious this phenomenon is.2.The frequency domain analysis method is used to study the impact of blast impact on the ship propulsion shaft system.When the ship propulsion shaft system is subjected to blast impact load,the propeller and tail shaft are the most affected,while the crankshaft and intermediate shaft are relatively less affected.The impact spectraof acceleration in different directions have different effects on the shafting.3.Ship collision simulation was carried out in the ANSYS ls-dyna module to obtain the dynamic characteristics of propulsion shafting under different collision speeds,different rotational speeds and different ship dynamic stiffness.The simulation results show that the response characteristics of the shaft system are greatly affected by the rotational speed of the shaft of the collided ship.The stress is mainly concentrated in the bearing position,among which the stress of the tail bearing and the amplitude of the propeller are the largest,and increase with the rotational speed of the shaft.In the process of ship collision,the amplitude of each part of the shaft in the transverse direction is the largest,and is much larger than that in the longitudinal direction and the vertical direction.The amplitude of the propeller is larger than that of other parts of the shaft,and the amplitude of the intermediate shaft is the smallest. |
