Analysis Of Protection Property And Damage Mechanism Of Woven Multi-shock Shields Under Hypervelocity Impact

With the progress of science and technology,human life and space activities are increasingly inseparable.The booming of space industry has also caused the deteriorating of space debris environment.Aiming at the threat of space debris on the spacecraft,a variety of new protective structures has been developed on the basis of traditional aluminum alloy shields.Basalt fiber shield is lighter in quality and has the properties of reducing the speed of the project and speeding up the break of the projectile.Based on the previous research work,this paper studied the damage mechanism and protective performance of basalt fiber shields by combining theory and experiment,and discussed the damage mechanism of the projectile with the high speed.The main research works include:Under the influence of the shear force work,the deformation energy of the shield plate and the impact heat,the residual velocity of the projectile impact ing single layer aluminum plate was studied.The critical impact velocity of the fiber fusion was determined and the value varies with the diameter of the projectile.According to the cumulative damage model,the temperature of the basalt fiber was calculated.It was confirmed that the basalt fiber was mainly stretched and sheared in the ballistic range.In addition to the above two kinds of destruction,the fibers also occurred melting damage in the shatter range.Based on the hypervelocity impact tests,the damage appearance of projectile was obtained.Many small gully and spine exist on the surface of the missile body and the depressed areas exist on the back of the missile body obviously when the projectile impact basalt fiber shields.The depth of the depressed area varied with the number of fiber cloth when the impact velocity was similar.While,the remaining body was smoother and the depressed area in the back of missile body was not apparent when the projectile impact the aluminum plate.The mass and thickness of the remaining projectiles varies with the velocity and the type of protective shields.According to the weaving characteristics of basalt fiber cloth and the theory of shock wave,the damage mechanism of residual projectile was analyzed.The rugged surface was formed because of the grooves formed when the projectile impacted the fiber wire,the increasing initial impact point and the braided structure of the basalt fiber cloth.The generation of the depression area was promoted by the increased temperature and pressure in the projectile body.The existence of body crack was related to the reflection of strong elastic-plastic wave on the free surface.Based on the theory of hydrodynamics,the crater depth equations were proposed.The empirical equation of perforation diameter and the bulge of the rear were deduced when the projectile impacted the stuffed shielding with basalt and Kevlar fiber clothes.The influence of the physical parameters such as the impact velocity,the diameter of the projectile and the distance between the shield on the bulge and the perforation diameter were discussed.