Dynamic Design And Analysis Of A Reusable Rocket's First Stage

In order to save costs and improve the cushioning performance of the rocket's first-stage,the rocket landing recovery process is studied.The main method of research is the combination of finite element simulation and theoretical analysis.The first method of recovery is impact into water.The research process is as follows: Firstly,use the finite element software to simulate the impact process of the rocket 's first-stage into water;To verify the accuracy of the simulation results,compare them with the theoretical results of the undamped free vibration theory.Then study the influence of initial speeds and angles on rocket's overload.It is found that under the same conditions,the greater the initial vertical velocity of the rocket's first-stage,the deeper it impacts into water and the larger vertical overload it gets,but the overload in the horizontal direction is not affected.The smaller the angle between the axis of the rocket's first stage and the horizontal plane,the shallower it impacts into water,and the greater the horizontal overload it gets.The second recovery method is using the airbag landing buffer.The research steps are as follows: Firstly,based on the central difference method,a new theoretical calculation method of the airbag cushioning system is proposed;Then establish a finite element airbag model and compare the results of them to verify the accuracy of the new method.After that,the method is used to calculate the landing process of the rocket's first stage landing with cushion airbags.The maximum overload and the angular velocity of the airbag are calculated when the rocker's first stage hits on different landing points of a complex terrain.The adaptation of the airbag cushioning system in the complex terrain is analyzed.Finally,we could obtain the appropriate landing point location of the rocker's first stage.