Research On The Structural Design And Penetration Characteristics Of A Deep Space Impactor

Deep space impactors can invade asteroids to obtain information about the shallow surface of the object,which can provide a basis for preventing asteroids from hitting the earth,and analyze the laws of asteroid motion,etc.,which is one of the research hotspots in space activities at present.The impactor should not only meet the requirements of penetration depth and strength,but also have enough cavity volume and high overload resistance in the structural design.In this dissertation,an impactor structure is designed and optimized.At the same time,the penetration characteristics of the impactor are studied,which has important reference value for the subsequent design of the impactor.In this dissertation,the main research contents and conclusions are as follows:(1)A kind of impactor structure is designed based on the main technical indexes required by the overall scheme of deep space exploration.The structural parameters and material parameters of impactor are determined.The numerical model of impactor penetration is established by using the explicit dynamic finite element program ANSYS/LS-DYNA.The movement characteristics and shell strength of impactor are analyzed,which lays the foundation for structural optimization of impactor.(2)The theoretical model of vertical penetration of impactor is established based on the theory of cavity expansion,and the sensitivity of impactor’s shape parameters is analyzed with Sobol index method.The sensitive parameters of impactor’s overload peak,cavity volume and mass are obtained.With the help of the surrogate model technology,the shape of the impactor is optimized,and the shape of the impactor with the maximum cavity volume and the minimum penetration overload is finally obtained.(3)By numerical simulation,the oblique penetration model of the optimized rear impactor is established,and the effects of inclination and angle of attack on penetration trajectory,depth,overload,velocity and shell strength,as well as the effects of initial velocity on penetration depth and overload peak of impactor are studied.(4)The ground penetration test plan of impactor is designed,the ground penetration test of impactor is carried out,and the incident phenomenon of impactor is obtained.The test and numerical simulation results are compared,and the accuracy of the two is mutually proven.