This study presents the ballistic limit velocity of small caliber projectiles against SS400 steel plate derived from live-fire ballistic experiments. Four different small caliber projectiles were tested against SS400 ...This study presents the ballistic limit velocity of small caliber projectiles against SS400 steel plate derived from live-fire ballistic experiments. Four different small caliber projectiles were tested against SS400 steel plates of 9 mm, 10 mm, and 12 mm thicknesses. The ballistic limit velocity was calculated using two standard methods, MIL-STD-662F and NIJ-STD-0101.06, and additionally using a support vector machine algorithm. The results show a linear relationship between the plate thickness and ballistic limit velocity. Further, the relative penetration performance among five different small caliber projectiles was analyzed using the Penetration Performance Ratio(PPR) introduced in this study, which suggests the potential of PPR to predict the ballistic limit velocity of other untested materials and/or different projectiles.展开更多
In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible couplin...In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible coupling multi-body dynamic model of the large caliber machine gun with muzzle brake based on floating principle was established,in which the influence of soil and human body was taken into account.The dynamic simulation was conducted and then the results were compared with the corresponding experimental data The dynamic characteristics of the machine gun with or without floating technique were analyzed to indicate the influence of floating technique upon the performance of the gun.Furthermore,the rigid-flexible coupling dynamic models with five different firing angles was constructed to study the influence caused by the angles.The results indicated that the floating mechanism could reduce the recoil effectively and improve the operational performance of this novel large caliber machine gun.展开更多
The non-scaling effect on the penetration depth of rigid projectiles is an important issue that must be considered when extending the results of scaled experiments to prototype scenes.In this study,the evolution of th...The non-scaling effect on the penetration depth of rigid projectiles is an important issue that must be considered when extending the results of scaled experiments to prototype scenes.In this study,the evolution of the stress and strain of the target under penetration was analyzed.Expressions for the penetration resistance and penetration depth were obtained based on the conservation equation and continuity condition of the target.The penetration coefficients that characterize the nose shape,target resistance,and non-scaling effect were defined.Simplified calculation methods for the coefficients within the range of rigid projectile penetration were developed.Two methods for estimating the target parameters are proposed.The results show that the non-scaling effect is related to the failure process of the target and depends on the ratio of cavity radius to comminuted region radius.The nose shape coefficient can be approximated as a linear function of the length-to-diameter ratio of the nose.The noseshape coefficient of a flat-nosed projectile is 0.57.The caliber coefficient is related to the projectile diameter and reflects the non-scaling effect,which increases with the projectile diameter.A practical formula for calculating the penetration depth of rigid projectiles considering the non-scaling effect is also proposed.This formula is in good agreement with penetration experiments on rock and concrete.展开更多
文摘This study presents the ballistic limit velocity of small caliber projectiles against SS400 steel plate derived from live-fire ballistic experiments. Four different small caliber projectiles were tested against SS400 steel plates of 9 mm, 10 mm, and 12 mm thicknesses. The ballistic limit velocity was calculated using two standard methods, MIL-STD-662F and NIJ-STD-0101.06, and additionally using a support vector machine algorithm. The results show a linear relationship between the plate thickness and ballistic limit velocity. Further, the relative penetration performance among five different small caliber projectiles was analyzed using the Penetration Performance Ratio(PPR) introduced in this study, which suggests the potential of PPR to predict the ballistic limit velocity of other untested materials and/or different projectiles.
基金supported by the National Natural Science Foundation of China under Grant No.11802138China Postdoctoral Science Foundation under Grant No.2018T110503the Fundamental Research Funds for the Central Universities under Grant No.30918011302
文摘In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible coupling multi-body dynamic model of the large caliber machine gun with muzzle brake based on floating principle was established,in which the influence of soil and human body was taken into account.The dynamic simulation was conducted and then the results were compared with the corresponding experimental data The dynamic characteristics of the machine gun with or without floating technique were analyzed to indicate the influence of floating technique upon the performance of the gun.Furthermore,the rigid-flexible coupling dynamic models with five different firing angles was constructed to study the influence caused by the angles.The results indicated that the floating mechanism could reduce the recoil effectively and improve the operational performance of this novel large caliber machine gun.
基金the National Natural Science Foundation of China(Grant Nos.52422808,52378401)to provide funds for this research。
文摘The non-scaling effect on the penetration depth of rigid projectiles is an important issue that must be considered when extending the results of scaled experiments to prototype scenes.In this study,the evolution of the stress and strain of the target under penetration was analyzed.Expressions for the penetration resistance and penetration depth were obtained based on the conservation equation and continuity condition of the target.The penetration coefficients that characterize the nose shape,target resistance,and non-scaling effect were defined.Simplified calculation methods for the coefficients within the range of rigid projectile penetration were developed.Two methods for estimating the target parameters are proposed.The results show that the non-scaling effect is related to the failure process of the target and depends on the ratio of cavity radius to comminuted region radius.The nose shape coefficient can be approximated as a linear function of the length-to-diameter ratio of the nose.The noseshape coefficient of a flat-nosed projectile is 0.57.The caliber coefficient is related to the projectile diameter and reflects the non-scaling effect,which increases with the projectile diameter.A practical formula for calculating the penetration depth of rigid projectiles considering the non-scaling effect is also proposed.This formula is in good agreement with penetration experiments on rock and concrete.
