Study On Force And Rails Deflection Of Augmented Electromagnetic Rail Launcher

Electromagnetic rail launcher is a new kind of launcher,which can accelerate the armature to ultra high speed.It uses electromagnetic force to drive the armature,converts electromagnetic energy into mechanical energy.Electromagnetic rail launcher is widely studied and applied the modern military field,and will partially or completely replace the traditional emission mode.During the launching process of the electromagnetic rail launcher,the rail will produce transverse deformation under extremely complex loads,due to the electromagnetic,thermal,mechanical effects.That result will effect on the launch accuracy and service life of electromagnetic rail launcher.Therefore,the research on the force and deformation of electromagnetic rail launcher has important theoretical significance and practical value.In this dissertation,the two-turn augmented electromagnetic railgun is studied as the subject.The simulation model is established using finite element software Ansoft.Based on the simulation results,the current distribution in the rails and the armature is analyzed and reasonably assumed.According to the magnetic field superposition principle and BiotSavart's law,the electromagnetic force of the armature is derived.The kinetic equation is established and solved by using the software Matlab.The theoretical results of the displacement,velocity and electromagnetic force of the armature is compared with the simulation results,and the correctness of the hypothesis is verified.The influence of the launcher parameters on the electromagnetic force of the armature is analyzed.The electromagnetic force of the rails is derived according to the magnetic field superposition principle and Biot-Savart's law.The formula is solved numerically by using the software Matlab.At the same time,the theoretical results of the electromagnetic force of the rails are compared with the simulation results,and the correctness of the hypothesis is verified.The influence of the launcher parameters on the electromagnetic force of the rails is analyzed.By using ANSYS software,the magneto-thermal-structure coupling of the electromagnetic launcher is analyzed.The current density,the temperature distribution,the temperature change with time of the armature and the force of the armature heat expansion on the rail are obtained.At the same time,the force of the armature on the guide rail under the electromagnetic field and thermal expansion is compared and analyzed.According to the theory of beam on elastic foundation,the flexural differential equation of rails is established.The equation was solved by unit initial parameter method,The deformation law of rails under external load and the influence of elastic foundation coefficient on rails deformation are analyzed.