Study On Damage Characteristics Of Whipple Protective Structure Under Hypervelocity Impact

In recent years,with the increase in human space activities,the number of space fragments has also increased rapidly,which has a serious threat to the security of astronauts and space equipment.Related studies include experiments and numerical simulation analysis of hypervelocity impacts,as well as design optimization of new protective materials and structures.At present,there are many experiments and simulation research on the hypervelocity impacts,there are few studies on the hypervelocity oblique impact of a projectile on the Whipple protective structure.However,the impact posture of tiny fragments on the protective structure of the spacecraft is mostly oblique,and the fragmented clouds generated by the inclined impact expansion are wider than the fragments generated by the positive impact.The phenomenon of sliding bombs will cause serious damage to the external equipment of the spacecraft.Therefore,it is particularly important to study the design optimization of spacecraft by studying the Whipple protective structure for hypervelocity oblique impact of projectiles.Among them,The impact yaw angle and angle of attack on debris clouds are particularly noticeable.The object of the above research is mostly spherical projectiles,and under the same impact conditions,the damage ability of cylindrical projectiles is stronger than that of spherical projectiles of the same mass.Therefore,it is necessary to conduct in-depth research on the damage characteristics of cylindrical projectiles during hypervelocity impact on Whipple protective structures.Based on the above background,the paper will carry out the research on the hypervelocity impact of cylindrical projectiles with different length-diameter ratios on Whipple protective structure.The length-diameter ratio of cylindrical projectiles includes 0.5,1,2,4,etc and the yaw angle and attack angle in oblique impact include 15°,30°,45°,60°,75°.Using AUTODYN-3D software to carry out numerical simulation,the simulation results such as the perforation characteristics of the front target,the debris cloud morphology characteristics,the debris feature information,and the damage of the rear target of the cylindrical projectile under different aspect ratios and different impact posture are obtained.(1)When the projectile is directly impacting the target,the perforation size of the front target decreases with the increase of the aspect ratio;When the projectile targets are impacted at different yaw angles,the perforation damage of the front target is the largest at a yaw angle of 75°;When the projectile targets are impacted at different angles of attack,the perforation damage caused by the projectile with the same aspect ratio is the largest when the angle of attack is around 45°.(2)The mass and kinetic energy of large and larger debris are much higher than those of small debris,which are the main influencing factors for rear wall damage.(3)With the increase of the yaw angle and attack angle of the missile target,two impact damage regions gradually form on the rear target,with the maximum damage to the rear target occurs near an impact angle of 45°.