| At present,scholars at home and abroad mainly focus on the maneuverability of ships,which is an important index to measure the navigation performance of a ship.There are two main methods to study the maneuverability of a ship: the integral method and the separation method(MMG).Because the integral method requires high data and has a narrow applicability,the separation method has become the main method to study the motion of a ship.Scholars at home and abroad use MMG to build a ship’s four or six degree of freedom maneuvering model in still water.The forces acting on the ship include the inertia force and viscous force of the naked hull itself,the propeller force and rudder force generated by the propulsion device,and consider the interaction among the hull,propeller and rudder,and then jointly analyze the ship’s different wind,wave and current In this paper,the "separation method"(MMG)and multibody dynamics are proposed to study the dynamic response of ships.In this paper,based on the ANSYS-SCDM platform,the ship three-dimensional solid model is built.According to the thought of "separation method"(MMG),the ship’s motion model is built for the mathematical model of naked hull,propeller and rudder.Then according to the actual engineering requirements,the other forces and moments on the ship are exerted by the multi-body dynamics,so as to build the joint dynamic simulation model and carry out the research on the ship’s multi-body dynamic response.In this paper,the ship dynamic joint simulation research is carried out with the example of transport ship,navigation aid mark ship and self unloading sand ship.(1)This paper analyzes the ship’s motion state and the maximum forward transverse flow that it can bear under different conditions when the ship is anchored by the horizontal vertical pole.The results show that with the increase of the cargo capacity,the displacement of the ship increases,the center of gravity decreases,the anti overturning ability decreases,and the anti flow ability decreases.(2)This paper analyzes the dynamic response of the navigation aid sign ship under the fluid force and the anchor chain load,and determines the suitable lifting system of the navigation aid sign ship.The results show that the combination of bow anchor block and balance block can meet the requirements of lateral displacement,longitudinal displacement and vertical displacement for the navigation aid sign ship under the condition of water level rise and fall of the navigation aid sign ship.The design scheme is feasible.(3)This paper analyzes the influence of the ship’s motion state and stability when the conveyor belt frame of the dump ship rotates horizontally at different angles and speeds.The results show that with the increase of the turning angle of the conveyor belt frame,the change of the heeling decreases,and with the increase of the turning rate of the conveyor belt frame,the change of the heeling increases.(4)From the above three ship dynamics studies,we can see that the ship dynamics joint simulation based on "separation method" and multi-body dynamics established in this paper can solve the practical engineering problems,and provide a reference for the similar problems. |
