Modal Matching Analysis And Optimization Of A Naval Gun

This paper takes a naval gun as its research background. In order to improve the guns overall dynamic performance, the modal matching analysis is studied for structural performance analysis and dynamic optimum design. Aiming at the local structure nonlinear problem of the gun weapon, firstly, identify modal parameters of major components by linear modal theory, and then take the impact of various mechanical joints into consideration on dynamic performance of the naval gun to figure out the overall dynamic performance and dynamic response of the naval gun structure, then, on this foundation, multi-objective optimal matching analysis is carried on for the modal parameters of primary parts of the naval gun, seek the best design meeting the conditions. At the end, use the topology optimization technology combined with the naval gun firing dynamics analysis to verify the feasibility of the scheme.The main content as the follows:1. Discuss the method and procedure of establishing the finite element model, then, establish 3D model of every part of the naval gun and mesh it, establish the finite element model of the whole naval gun with proper way of joints.2. According to the theory of modal analysis, with the finite element method, get the inherent modal shape of primary components of the naval gun such as body tube, cradle, bracket, turntable, and take the impact of various mechanical joints into consideration on dynamic performance of the naval gun from the whole system, characterize the joints stiffness and damping characteristics by using spring damper unit provided by ABAQUS, and also, analyse the overall dynamic performance and dynamic response of the whole naval gun model.3. Put forward the way that use response surface-Behnken-design (BBD) to select the sample points to establish the approximate function relation of the design parameters(frequency of the components which are sensitive to the muzzle vibration) and response goals(the muzzle angular displacement and the linear velocity of transverse vibration), combine the satisfaction function method to optimize response goals, to make it synthesize optimal and acquire the best frequency matching scheme reaching the goal of reducing the muzzle vibration through frequency matching optimum4. Use the topology optimization technology combined with the actual operating conditions and dynamic performance analysis of the bracket, solve the multi-constraints and multi-goals bracket topology optimization SIMP model according to variable density method based on ABAQUS/ATOM module., and optimize and improve the bracket structure according to the density cloud picture, realize the lightweight of the structure and meanwhile, ensure an obvious improvement of bracket dynamic performance.