Structural Design And Simulation Analysis Of A Concentric Eddy Current Damper For A Howitzer

When the artillery fires projectiles,the gunpowder gas will produce a very short action time and a large peak bore resultant force.This puts extremely high requirements on the design of the recoil system of the artillery.The recoil mechanism is one of the key components of the recoil system of the artillery.In long-term use,there are problems such as leakage and failure of the recoil liquid for gun,which reduces the reliability of the recoil performance.The eddy current damper is a non-contact braking device based on the principle of eddy current damping.It has the advantages of simple structure,reliable braking force and environmental protection.It can avoid the problems existing in the long-term use of traditional recoil brake.The eddy current damper is applied the recoil system of the artillery is of great significance to improve the stability of the artillery performance.This paper takes a howitzer recoil mechanism as the research object,proposes a cylindrical permanent magnet eddy current damper,and analyzes its transient damping characteristics under strong impact load,electromagnetic fieldtemperature field coupling analysis,research on the optimization of recoil resistance based on eddy current damper and simulation analysis of the dynamic characteristics of artillery fire.The main contents of the full text are as follows:Firstly,a magnetic circuit structure based on an improved Halbach array is proposed,magnetic circuit design materials are selected,different magnetizing methods are compared,and a concentric cylindrical permanent magnet eddy current damper is designed.Secondly,a finite element simulation model was established by use the multiphysics simulation software COMSOL,and the Halbach array and the eddy current damper were respectively simulated for steady-state static magnetic field and Transient damping characteristics under strong impact load based on the recoil equation of the artillery,and compared and analyzed.The key size parameters of the eddy current damper and the influence of the coaxial eccentricity error on the damping characteristics are discussed.The simulation results show that the unilateral magnetic field and self-shielding effect of the Halbach array can effectively improve the utilization rate of permanent magnets and reduce the mass of the eddy current damper;under the common load excitation of the bore resultant force and the counterrecoil force,the eddy current damper The damping characteristics can meet the performance requirements of the anti-recoil of the artillery.Thirdly,Aiming at the sudden change of recoil resistance caused by "demagnetization" effect,a comprehensive use of experimental design,finite element numerical simulation and approximate model technology to optimize the recoil resistance platform of the eddy current damper was proposed,and the recoil resistance optimization model of the eddy current damper was established.The genetic algorithm solves the model,the optimized recoil resistance curve fluctuates little,and the recoil velocity and recoil displacement change law basically unchanged.Fourthly,aiming at the temperature rise change of the eddy current damper caused by the induction heat generation of the conductor inner cylinder,a finite element model of electromagnetic field-temperature field coupling(electromagnetic heating)was established using COMSOL software and simulated calculations.The simulation results show that the temperature rise is mainly concentrated in the conductor on the cylinder,the permanent magnet array will not affect the performance of the eddy current damper due to high temperature demagnetization.Fifthly,a finite element model of the artillery using concentric eddy current dampers was established,and the finite element numerical simulation calculation of the dynamic characteristics of artillery fire was carried out.The dynamic stress and displacement response of the artillery structure and the muzzle vibration response based on the eddy current dampers were obtained.The comparison of the simulation results showed the overall structural rigidity of the artillery has not changed significantly,and the muzzle vibration response is better.The concentric eddy current damper proposed in this paper can meet the fire requirements of howitzer,and has a wide range of engineering application value and prospects.