Investigation On The Resistance Performance Of 2A12 Aluminum Alloy Corrugated Sandwich Plate Against Projectile Impact

The corrugated sandwich structure has been widely used in the aviation field,so it is of great practical significance for the design and maintaining of the aircraft structure to study the impact resistance of this structure when it is impacted by foreign objects.However,there are relatively few relevant researches at home and abroad,and there are few comprehensive and systematic analysis of the influence mechanism and transformation mechanism of different factors on their protective performance.This paper takes 2A12 aluminum alloy corrugated sandwich plate as the research object,and a combination approach of experimental and numerical simulation methods is adopt to study the impact resistance of the target under the normal impact of high-strength metal projectile,and the influence law and mechanism of the shape of the projectile nose,the impact position of target and projectile,the impact velocity,the geometry size of target on the impact resistance performance and energy absorption characteristics of the target are analyzed.Firstly,an experimental study on three kinds of projectiles impact circular corrugated sandwich plates and blunt-nosed projectiles impact equivalent single-layer plates were carried out by using the one-stage light gas gun.The results show that the circular corrugated sandwich plate exhibits different impact resistance for different impacts of the projectile,and its performance against the impact of ogival-nosed projectiles are the best,and hemispherical-nosed projectiles are the second,the performance against the impact of blunt-nosed projectiles are the worst.The impact resistance performance of the equivalent single-layer to blunt-nosed projectiles are better than that of circular corrugated sandwich plate which is set experimentally.According to the above rules,the mechanism analysis was carried out from the process of the projectile impact target,the failure mode of the target plate and the energy consumption angles.Secondly,with the finite element software ABAQUS,the corresponding model of projectiles impact targets are established for the experimental conditions.Through comparing experimental and simulation results,it is found that the ballistic limit speed of the numerical prediction is close to that of experiment,the process of the projectile impact target is consistent,and the failure mode of the target plate is in good agreement,and the validity ofthe simulation model and its parameters are verified.Finally,the effects of the impact position,the geometry size of the target on the impact resistance of the corrugated sandwich plate were analyzed.The research shows that the impact resistance of the target is affected by the impact position of the projectile.In the case of the node position of target plate is impacted,the ballistic limit velocity is the highest,the middle position is the second,and the base position is the lowest.The geometry size of target has a significant effect on its impact resistance,the ballistic limit velocity first decreases rapidly and then increases slightly with the increase of the target core height.Increasing the thickness of the core or the back plate can significantly improve the impact resistance of the target.According to the above rules,the influence mechanism and transformation mechanism are analyzed from the perspective of target failure mode and energy consumption.In summary,the impact resistance,failure mode and energy absorption of aluminum alloy corrugated sandwich plates under different influence factors have been systematically studied in this paper.The results can provide reference and basis for optimizing the size of corrugated sandwich structure.This is of practical engineering significance to improve the ballistic protection performance of the structure.