Research On Anti-fragment Penetration Performance Of Q235 Steel Laminated Target

In order to study the anti-penetration performance of the laminated target and its layered structure against fragments of different shapes,this paper selects Q235 steel single-layer and double-layer stack targets of the same thickness,and the double-layer targets were combinated with different structure.The ballistic limit velocities of the two kinds of fragments penetrated Q235 targets with different structures were obtained,and the failure modes of the two kinds of fragments penetrated Q235 targets with different structures were analyzed.In order to study the factors affecting the anti penetration performance of laminated target,the numerical simulation was carried out by using LS-DYNA software,and the penetration results of different layered structure targets were obtained,including fragment shape,fragment mass,fragment landing attitude and initial impact velocity.Numerical results show that under the condition of the same fragment quality,the ability of the laminated target to resist the penetration of hexagonal prism fragments is better.This is because the hexagonal prism fragments need to consume more energy during the pit stage.With the gradual increase in the mass of the fragments,the influence of the shape of the fragments and the landing attitude of the hexagonal fragments on the ballistic limit gradually weakens;when the masses are the same,fragments of different shapes have different influences on the anti-penetration performance of the laminated target.However,reasonable stratification can obtain better anti ballistic performance than single-layer target with equal thickness.The initial impact velocity of fragments has an important influence on the state of fragments after the penetration of the fragments.The higher the initial impact velocity,the more obvious the deformation of the fragments and the larger the aperture of the target plate.When the initial impact velocity exceeds a certain value,the fragments will be broken,which is caused by the stress of the fragments exceeding the strength limit.On the basis of experiments and numerical simulations,theoretical models of spherical fragments and hexagonal prism fragments penetrated the target plate were established according to the failure mode of the fragments penetrated the target plate,and the deformation energy of the fragments was considered.The various energy consumption and total energy consumption during the penetration process were calculated.The calculation results show that when the spherical and hexagonal prism fragments penetrate the target,the main energy is used for inertial compression energy consumption,shearing punching energy consumption,reaming energy consumption,target depression energy consumption and fragment deformation energy consumption.For target of different structures,the types and proportions of energy consumption are different.The theoretically calculated total energy consumption is highly consistent with the experimental total energy consumption,which verifies the accuracy of the model.The above research conclusions have important reference value for the structural design of the fragmented warhead and the protective structure design of the laminated target.