| Since the beginning of the 20th century,human space activities have become increasingly frequent,and the amount of space debris generated has also increased sharply.Its hypervelocity impacts have become more and more serious to the safety of spacecraft in orbit.After the space debris hits the protective structure of the spacecraft at hypervelocity,a large number of debris clouds will be formed,which can easily cause secondary damage to the spacecraft.Therefore,it is extremely necessary to study the debris cloud formed by hypervelocity impact.So far,the research on the debris cloud has mainly focused on spherical projectiles.At present,there is still a lack of research on the debris cloud of non-spherical projectiles.However,the debris in the space environment is mainly non-spherical.Among them,cylindrical and conical projectiles are paired.The damage performance of the thin plate is the greatest.When space debris collides with a spacecraft,its attitude is oblique impact.At present,the attitude of research projectiles is almost always the attitude of positive impact,and there is still a lack of research on debris clouds that impact in different attitudes.Based on the above background,the paper will conduct research on the morphological characteristics of debris clouds under different impact angles.With the help of Auo DYN-3D software,using SPH numerical simulation method,by changing the aspect ratio α(0.1～20.0)of the cylindrical projectile,the geometric characteristic parameters,characteristic fragment velocity and fragment cloud distribution of the formed debris cloud are studied,so as to obtain a representative The length-diameter ratio of the cylindrical projectile.On the basis of different aspect ratios,the influence of different impact angles(15°,30°,45°,60°,75°)on the geometric characteristic parameters of the debris cloud,the characteristic particle velocity and the characteristic parameters of the debris distribution are further considered.The research results show that:(1)When the length diameter ratio of projectile is 1,the most fragments are formed.When the impact angle is 60° The expansion range of debris is the most extensive,and the proportion of dangerous debris is about 99.0%;The proportion of dangerous debris is about0.9%,which is mainly distributed in the ring within 10 mm near the center;The proportion of small debris is about 0.1%,mainly distributed in the periphery of the central point.(2)The change of projectile impact attitude has an impact on the number of debris clouds.Among them,the debris cloud formed by oblique impact is always larger than that formed by positive impact,and the impact angle is 60° The number of fragments formed is the largest when the ratio of length to diameter changes.(3)With the change of the aspect ratio,the fragmentation degree of the projectile decreases gradually,the expansion range of the debris cloud decreases gradually,and the kinetic energy of the debris cloud increases gradually,which reaches the maximum when the aspect ratio is 0.5.(4)With the change of impact angle,the axial and radial expansion range of the debris cloud gradually decreases,and the velocity of the farthest point in the axial direction of the outer bubble debris cloud,the velocity of the farthest point in the axial direction of the main debris cloud and the velocity of the farthest point in the axial direction of the debris cloud gradually decrease.When the impact angle is greater than 45° At the same time,the range of debris cloud gradually shrinks,and the back splashing phenomenon of projectile material becomes more obvious.The perforation diameter of the thin plate first decreases and then increases with the increase of the impact angle,and the maximum damage degree of the projectile occurs when the impact angle is 45°。... |
PDF Full Text Request