Research On The Resistance Performance Of Double Aluminum Alloy Target

Civil aviation aircrafts are often threatened by the impact of foreign objects during its flight,therefore,the study of the impact resistance of aircraft protection structure has practical engineering application value.The high-strength aluminum alloy has been widely used in aircraft strength structure,because the weight of the strength structure is one of the most important factors in the design.The existing protective structure used on existing aircraft is mainly a single-layer structure,and this structure has various defects,so double-layer protective structures,as a potential optimization method for single-layer structures,have received more attention.In this paper,the 2A12-T4 aluminum alloy thin plate is taken as the research object,and the influence law and mechanism of the impact angle of the impact object,the layer number of the target and the inter-plate gap on the impact resistance of the protective structure are studied.Firstly,the gas gun system was been used to carried out the projectile impact test,and the blunt projectile has been used to impact three types of 2A12-T4 aluminum alloy targets.The impact results have been written by high-speed camera,and the ballistic limit speed has been calculated through the model.Based on the experimental results,the impact resistance of performance of the single-layer aluminum alloy plate is higher than that of the contact double-layer,and the impact resistance performance of the gap double-layer target plate,which presents three situations: high,medium and low,is affected by the posture of the projectile and the interference of the plug.Secondly,the projectile impact model for the experimental conditions has been built according to the J-C constitutive model and failure criterion by the ABAQUS/Explicit finite element software.The experimental results and simulation results are compared to verify the effectiveness of the simulation.Based on the numerical simulation,the study on the influence of discrete debris on the impact resistance of the target is carried out.It is found that the impact resistance performance of the target increases first and then decreases with the increase of the interference area between the projectile and the debris.Thirdly,through the numerical simulation,three kinds of target plates impacted by blunt projectile at different angel have been studied.Comparing the simulation results underdifferent working conditions,the impact resistance of the structure decreases first and then increases with the increase of the angle of the projectile,and with the increase in the number of the layer of targets and gap between the plates,the impact resistance of the three kinds of structures shows a downward trend.In this paper,the impact resistance performance of the double-layer 2A12-T4 aluminum alloy plate is systematically studied.The effects of various factors on the failure of the structure under different working conditions are studied,and the change law and transformation mechanism of impact resistance performance and failure mode of the double-layer aluminum alloy structure impacted by the blunt projectile are revealed.The research results can provide reference for the design of aircraft protection structure.