The Vulnerability Research And Protection Scheme Design Of An Armed Helicopter To Small-caliber Kinetic Energy Bombs

In order to study the defense strategy for a gunship against small caliber kinetic energy（KE）projectiles,the damage criteria of rotor wings and transmission shaft were established,further more,the vulnerability model of gunship was built.According to this model,The vulnerable area in typical strike directions were calculated by the method of“grids scanning”,which helped to find out the vulnerable position of a gunship.In addition,hit probability of critical components in the gunship was calculated,combined with considering the consequences if the components were damaged,the importance of components was ranked.Besides,the bottom of the gunship was divided into several regions,the minimum armor thicknesses required of these regions was calculated,and so were the regions’defense effectiveness.Based on the defense effectiveness and the importance of critical components inside,the defence strategy was proposed.Regard to KK level damage,the vulnerable area that gunship attacked from the lower left direction is 2.60 m²,which exhibits the highest vulnerability,yet if the gunship is attacked from its direct front or back,it exhibits the lowest vulnerability,its vulnerable area is 0.06 m².In the case of A lever damage,the gunship’s upper left side has the highest vulnerability,its vulnerable area is 4.83 m²,however,the gunship’s direct front appears the lowest vulnerability,its vulnerable area is 0.83 m².For C level damage,the vulnerable area that gunship attacked from the upper left direction is 7.52 m²,which exhibits the highest vulnerability,nevertheless,the gunship’s direct back has the lowest vulnerability,its vulnerable area is 1.61 m².While being attacked by projectile from the bottom,left or right engine of gunship has the highest hit probability,which is up to 48.53‰.Rear fuel tank has 46.97‰probability and front fuel tank has 41.79‰,which means the second and third high probability hit by projectile,respectively.For the sake of protecting inner critical components,magazine region of gunship requires at least 34.1mm 2A12 plate（equivalent）as its armor,while the tail region’s minimum armor thickness needs to be up to 58.7mm.Minimum armor thicknesses required by other regions are between the thicknesses value of the magazine region and the tail region.The regions’defense effectiveness calculation shows that rear cockpit region has the highest relative defense effectiveness,corresponding to KK,A and C level damage,its relative defense effectiveness are 15.38m^-1,15.54m^-1 and 17.78m^-1.however,the front cockpit region has the lowest relative defense effectiveness,which is 0m^-1,0m^-1 and 0.18m^-1,respectively.Under the condition of limited armor weight,the defense precedence of regions are sorted as follow:rear cockpit region,rear fuel tank region,port and starboard engine regions,front cockpit region,magazine region,port and starboard stub wing regions,tail regions,tailplane regions,nose equipment regions,port and starboard electronic equipment regions.