Impact Effects Of Stratified Structures In Space Debris Environment

With the increasing frequency of human space activities,the number of space debris is increasing.Hypervelocity impact of space debris will lead to the failure of surface structures and components of spacecraft,which is an important space environmental factor limiting the development of long-term effective,safe and reliable spacecraft.In this paper,the ground simulation of space debris environment is realized by using laser-driven flyer technology and SPH numerical simulation technology.The damage of SiO₂/AlN composite multilayer hard films under hypervelocity impact of micro debris was studied.The damage caused by hypervelocity impact on aerospace materials is characterized and analyzed.The process of impact damage and the influence of different impact parameters on the damage are further elaborated.In this paper,SiO₂/AlN multilayer composite structure films are designed.The results show that SiO₂/AlN multilayer composite films play a protective role against hypervelocity impact by observing the damage surface morphology and analyzing the numerical simulation.The more composite layers,the better anti-penetration performance.The impact damage of hypervelocity impact on SiO₂/AlN multilayer composite film is brittle fracture.There are extended cracks around the crack pit and on the surface of the film.Flyer speed and impact angle will affect the impact damage results.Increasing flyer velocity will lead to larger damage fragmentation zone and crack propagation zone.Increasing impact angle will lead to smaller vertical damage and larger radial damage.In this paper,three typical metal,inorganic non-metal and polymer materials are selected to simulate the hypervelocity impact on the ground.The results show that ductile fracture occurs in aluminium alloy and polyimide film,brittle fracture occurs in quartz glass.Local high temperature and high pressure occurs in hypervelocity impact,and phase transformation phenomena such as melting or vaporization occurs.The size,shape of the flyer and the thickness of target panel will also affect the damage of hypervelocity impact.The larger size of flyer,the larger the damage area.The damage caused by spherical projectile is more serious than that of plate projectile.The increase of target thickness will lead to the decrease of spallation phenomenon.