| In the ocean war,the protection technology and protection level of medium and large ships are increasingly enhanced,which is a severe test for the damage performance of anti-ship ammunition.In coastal operations,shore defense guns can play the functions of fire coverage and support.This paper designs a new anti-ship ammunition based on the large caliber shore defense gun platform,with the front stage being the axial multistage PELE warhead and the rear stage being the following semi armor piercing warhead,aiming to improve the penetration capability of anti-ship ammunition.The content of this paper provides reference for the research of anti-ship technology,and provides ideas for the research of the mechanism of PELE fragmentation effect.The research content of this paper only includes the following aspects:(1)According to the ammunition design theory and the PELE fragmentation effect mechanism,the new anti-ship ammunition meets the requirements of launch safety and flight stability.The shell material is 30 Cr Mn Si A after quenching and tempering,with high hardness and brittleness;The bullet core material is 1060 AL,the composition is approximately pure aluminum,the quality is soft,the strength is low and the density is small.When the alloy steel is extruded horizontally,the radial expansion of the shell will produce an ideal lateral effect;The tail part is designed to match the large-caliber smoothbore gun.The same caliber tail made of steel can not only provide kinetic energy for penetration,but also provide sufficient lift for flight.(2)The mechanical properties of anti-ship ammunition shell were studied.The quasi-static tensile tests were carried out on the tensile samples with different hardness of30 Cr Mn Si A.The average fracture strain of HRC50 tensile samples was 0.0267,the average fracture strain of HRC30 tensile samples was 0.0372,and the average fracture strain of unquenched and tempered tensile samples was 0.0747.It is inferred that the fracture strain is an important factor to control metal fracture.Then the ballistic test of PELE penetrating metal sheet was carried out.Through the recovery of PELE shell fragments,the size,mass distribution and fracture mode of the fragments were analyzed,and the fracture mechanism was revealed.Only the HRC50 shell PELE penetrates the3 mm target plate and produces the crushing effect,while the other hardness shell PELE penetrates the target plate and the projectile only produces plastic deformation and bending fracture.The analysis reason is that the loading distance and the actual loading are insufficient,and the radial strain of the shell does not reach the fracture strain of its material itself.(3)According to the plate frame structure of medium and large ships,and taking the measured metal shell fracture parameters as a reference,the numerical simulation study of anti-ship ammunition penetrating the three-layer spacing steel plate is carried out toexplore the change of the shell fracture process,target plate damage,and the axial residual velocity of the advancing semi-armor-piercing warhead when the material characteristics and the target parameters of anti-ship ammunition change,and to clarify the influence rule of its change on the anti-ship ammunition fracture effect and penetration ability;The fracture strain of shell material affects the scattered area,size and size of shell fragments of anti-ship ammunition;The strength and Poisson’s ratio of the core material are the main influencing factors of the lateral effect.If the strength is too low,it is not conducive to maintaining the overall structure of the anti-ship ammunition during the penetration process,and it will disintegrate in advance;The impact of the landing speed on the dispersion area of the shell fragments of anti-ship ammunition is relatively complex.In the range of 800m/s～1000m/s,the larger the landing speed is,the larger the dispersion area of the shell fragments is;The landing speed is in the range of 1000m/s～1100m/s.After penetrating the first layer of target plate,the rear structure of the front stage warhead is affected,which is not conducive to the crushing effect of the rear shell.The initial conditions such as the angle of attack and the angle of attack have a great impact on the damage effect and penetration ability of anti-ship ammunition.The larger the angle,the more obvious the damage area deviation and ballistic deflection,and reaching a certain value will make the penetration trajectory of anti-ship ammunition deviate from the target. |
