Study On Failure Characteristics Of Single Aluminum Plate Under Hypervelocity Impact

Mastering the response characteristics of space protection structures under hypervelocity impact will help to improve the optimal design of spacecraft protection structures.In this paper,experimental and numerical simulation are used to study the response characteristics of single aluminum plates of protective structures under hypervelocity impact.The main research contents and main results obtained are as follows:(1)Second development of AUTODYN software,adding SGL constitutive model into material model libraryThe SGL constitutive equation is automatically added to the material library through the AUTODYN secondary development interface using the Fortran language.The correctness of the secondary development of this paper is verified by the taylor bar collision calculation,and the necessity of SGL model for the calculation of hypervelocity impact is compared and analyzed.(2)The hypervelocity impact response of a single aluminum plate under the Mylar flyer at 7km/s-10km/sThrough the electric gun device,the ballistic limit experimental research of the Mylar flyer impacting the 6061-T4 aluminum plate was carried out,and a bifold line ballistic limit curve was obtained.When the impact velocity is in the range of 7km/s-8km/s,the critical mass decreases rapidly,and the critical mass of 8km/s-9.5km/s decreases slowly.(3)Numerical simulation of Mylar flyer 7km/s-10km/s normal impact and 30°oblique impact on aluminum plateThrough numerical simulation of normal impact and oblique impact,the aluminum plate failure process was analyzed.The calculation results show that when the flying piece is hitting the aluminum plate at a speed range of 7km/s-8km/s,the rapid decrease of the critical mass results from the rapid decrease of the shear strength of the aluminum plate under impact loading,which results in the decrease of its protective ability.In the speed range of 8km/s-9.5km/s,the change of the shear strength of the aluminum plate under the impact load is small,so that the critical mass change is small.In the case of oblique impact,as the impact velocity increases,the softening depth inside the aluminum plate increases,and the critical mass change is basically the same.(4)Numerical calculation and analysis of factors affecting hypervelocity impactThrough the numerical simulation of different configurations and masses of aluminum projectiles hitting a single-layer aluminum target at different speeds,the relationship between the projectile configuration,mass and the generated debris cloud was obtained.When the projectile is of the same mass,the cylindrical projectile has the strongest opening ability to the protective plate,the spherical projectile takes the second place,and the sheet weakens in order with the thickness.When the mass of the projectile is low(37mg),the momentum of the debris cloud generated by the cylindrical and spherical projectiles at a low speed impact is greater than that of the sheet projectiles.In the case of high-speed impacts,there is a maximum value for the debris cloud momentum of the sheet projectile,and the maximum value is greater than that of the cylindrical and spherical projectile debris cloud momentum.When the projectile has a large mass(1.0g),the momentum of the debris cloud generated by the cylindrical and spherical projectiles under a low-speed impact is large.Under high-speed impact,the debris cloud momentum of the sheet projectile increases with the increase of the thickness-diameter ratio,and the debris cloud momentum with a thickness-to-diameter ratio of 0.025 is smaller than that of cylindrical,spherical projectiles.