Research On Submarine Structural Deformation In The Equivalent Force System

Submarines are important means for sovereign states to maintain their own maritime security,which play an important role in the national defense construction system.With the modern design of the submarine,it continues to develop in the direction of large submersible depth and high speed.The problem of shaft alignment caused by hull deformation has also attracted more and more attention.The submarine shafting is mainly arranged in the stern of the submarine,and the two ends are respectively connected with the propeller and the power equipment.The deformation of the hull will change the relative position of each bearing of the shafting in the vertical direction,and change the alignment of the shafting thereby affecting the quality of shaft alignment.Therefore,the influence of hull deformation on shaft deformation is an important basis for measuring the safety performance of submarines.This article takes the simplified submarine as the research object,and adopts the idea of equivalent force system to study the influence of the hull deformation on the shaft system and bearings under the berthing and underwater conditions of the submarine respectively.The study provides reference.The main research contents of this article are as follows:1)Based on the idea of equivalent of force system,the principle of determining the boundary conditions of the submarine bow section cut-off model was proposed.Establish the balance equation of the force system of the submarine sitting pier and the submarine entering the water,and propose a method to calculate the deformation of the submarine structure using the submarine aft section model.The calculation method and process of hull deformation,shafting deformation and bearing centerline deformation are established,that is,the internal force of the submarine section is transformed into the boundary condition of the submarine cut surface.Based on this method,a submarine is taken as the research object by establishing a hull girder model,a hull stern model,and a hull hybrid model.The working load is applied to the berth and the underwater working conditions and the application method of the boundary conditions are given.2)The characterization method and control strategy of local deformation of submarine berthing equipment and structural parameters are studied using the submarine stern section model and applying equivalent boundary conditions at the section.It mainly includes the length of the section,the thickness of the pressure-resistant shell,the size and position of the partial openings of the equipment installation,and the influence of the equipment quality on the deformation characteristics.The deformation characteristics of the pressure shell and the shaft system and the relative deformation of the two are researched and analyzed,and a reference baseline is established in the state of bearing alignment.The centerline of each bearing of the submarine on the shaft alignment influence level when the submarine sits on the pier is obtained.3)A prediction method for the submarine stern structure’s key point equivalent to the dock pier condition deformation is obtained for the submarine’s underwater navigation state,using the submarine stern hybrid model.It mainly includes the influence of working water depth and the thickness of pressure-resistant shell on deformation characteristics.The deformation characteristics of the pressure housing and the shafting system and the relative deformation of the two are researched and analyzed,and a reference baseline is established in the state of bearing alignment influence level.