Analysis Of The Penetration Mechanism And Fracture Characteristics Of Fragile Armor-piercing Projectiles

The protection ability of guided missile,helicopter and other equipment are weak.If want to reach the wounded or destroyed,need to have strong aftereffect ability.In order to improve the after-effect capability of fragile penetrator,analyze the mechanism of fragile penetrator first,and then study the influence of different material properties on the projectile fragmentation characteristics and oblique penetration process broken phenomenon.Based on the stress analysis of projectile penetrating into each stage,study the influence of the incident velocity and target thickness on fragmentation characteristics.Studied the fragmentation characteristics of the fragile penetrator with triangle section shape that combined the action of triangle section on the stress,and did the ignition test.The conclusions as following:1)Study on the material properties of fragile penetratorIn order to study the influence of material properties of penetrator on fragmentation characteristics,by virtue of AUTODYN-3D finite element program,the whole impact process of the penetrator projectile with different different density and tensile strength penetrate finite thickness target was numerically simulated.By the physical model of the penetrator broken in the process of oblique penetrate finite thickness target,analysis the influence of material properties of penetrator on the breaking phenomenon.The results show that the fragmentation characteristics of penetrator is obviously improved with the decrease of tensile strength and the increase of density,and the breaking phenomenon occurred in the process of oblique penetration will further improve the fragmentation characteristics.This study provides theoretical basis for the production of fragile materials.2)The influence of target condition on penetration capability and fragmentation characteristicsIn order to study the influence of incident velocity and target thickness on the fragmentation characteristics,the fragmentation characteristics test is carried out in which the target velocity and target angle are varied.Meanwhile,based on the physical model of stress in the impact process of the fragile penetrator penetrate the finite thickness target.the influence of incident velocity and target thickness on the fragmentation characteristics was analyzed.Do the simulation that its working condition is the same as the test by the AUTODYN analysis software.The test and numerical simulation have good agreement.The results indicate that the fragmentation characteristics is improved with the increase of incident velocity and target thickness,and the range of the radial distribution of fragments is improved.In the test,the number of effective fragments accounted for the proportion of the total number of fragments increases with the increase of incident velocity and decreases with the increase of target thickness.3)The influence of section shape on penetration capability and fragmentation characteristicsIn order to study the fragmentation characteristics of the fragile projectile with triangular cross-section,taking the circular cross section fragile projectile which the cross section area and length are the same as the triangular cross-section fragile projectile as the contrast object.The fragmentation characteristics test is carried out in which the target velocity is in the range of 800m/s to 1200m/s and the target angle is in the range of 0° to 45°.Do the simulation that its working condition is the same as the test by the AUTODYN analysis software.The test and numerical simulation have good agreement.The results show that the incremental number of fragments is increased from the 15.9%of 800m/s to the 30.9%of 1000m/s;with the increase of the target angle,the incremental number of fragments is decreased from 29.0%of 0° to 23.6%of 45°.4)The influence of fragmentation characteristics on ignition characteristicsIn order to study the influence of incident velocity,target thickness and section shape on the ignition characteristics of fragile penetrator,based on the analysis of the ignition characteristics of fragile penetrator,the ignition test for 0#diesel oil was carried out.The results show that the ignition characteristics is improved with the increase of incident velocity;At a certain extent,the ignition characteristics is improved with the increase of target thickness and weakened with the further increase of target thickness;The ignition characteristics of the fragile projectile with triangular cross-section is better than the circular cross section fragile projectile under different target velocities and target angles.