Nonlinear Dynamics Analysis And Optimization Of Breech Extraction Mechanism

As an important component of shipboard artillery, the role of the breech extraction mechanism is to pull out the cartridge case left in bore after the artillery firing. Its work quality will directly affect the sustained combat capability of shipboard artillery, even influence the situation in the battlefield. Therefore, it is important to design the extraction mechanism for improving the reliability of shipboard artillery, Based on the breech extraction mechanism as the research object, the study aims to shape in the working process of extraction parts with nonlinear finite element theory and experimental design method for structural dynamics analysis and optimization research.The main contents are as follows:(1) The classical interior ballistics model is established in the bore to simulate the dynamic change. The MATLAB software is used to obtain the pressure load in the bore,comparing with the measured data demonstrate the validity of the results. Then, the mathematical model of cartridge resistance and the finite element model are respectively established to conduct the theory calculation and simulation, and the results of the two kinds of methods are used to carry out the comparative analysis to verify the validity of the simulation results.(2) According to the working principle of the extraction mechanism, the model is rational simplified in PROE. The establishment of whole finite element model is completed.by using HYPERMESH and ABAQUS to divide and set grid cell and defining the connection relations of components. Finally, the explicit algorithm of the nonlinear finite element method is carried out on the dynamics analysis of extraction mechanism and the stress distribution law of key components and the weak area of the structure are found out,which are regarded as the optimization goal.(3) Combined with dynamic simulation results, the study analyzes the dynamic response factors that affect extraction parts. The thesis is studied from the quality of parts and the speed of counter-recoil to use the orthogonal experiment to carry out the multiple-objective optimization for three key parts of the extraction mechanism. The optimal level of different factors is gotten, and then the optimal combination of a single target is seek out. The matrix analysis method is used to calculate the weight matrix of multiple target to determine the optimal combination plan. According to the optimal schemethe model is improved and compared the model optimization of dynamic characteristics of before and after the optimization of the optimization result is proved and the pump shell characteristics. The optimized stress of extraction parts got obviously improvement, the maximum stress of cartridge extractor reduces by 17.5% and radial maximum stress reduces by 13.4% and the maximum stress fell by 12.2% in the extraction template; The change of system energy is not large before and after the optimization, the average cast shell only fell by 0.36 m/s, which suggests that the optimized extraction mechanism has a little influence on its overall characteristics.