Numerical Simulation On The Forming Process Of Bar-cutting MEFP Warhead

The weapon system in the future should be suit for informationization, precision, andmulti-function, what is more, the ammunition is demanded to meet different kinds of target inthe battlefield. However, the traditional warhead structure with the single-EFP can onlyachieve the point-to-point attack, which cannot form the attack area, So the warhead can notdeal with the various types of armored targets. Bar-cutting MEFP can form axialmulti-fragments. Because the orientation and damaging effect, Bar-cutting MEFP can hit anddamage the armored targets, and destroy the light armored targets more effectively. Manycounties have made great effort to develop MEFP technology.Based on abroad review correlation technique inside and outside. Numerical simulationof the forming process of the different types of bar-cutting MEFP is carried out by usingLS-DYNA after the design of coss-shaped MEFP, astroid-shaped MEFP, circle-shaped MEFPwell-shaped MEFP, and forming influence of MEFP by many factors is analyzed. On thatbasis, Comparison and analyses of different types of bar-cutting MEFP is presented,and thebest schemed is obtained. Orthogonal optimization method is applied to analyze well-shapedMEFP. Penetration on steel target of EFP and well-shaped MEFP is contrasted and analysed.Research shows that（1）with the increasing of cutting reseau distance, and decreasing ofrod thickness, cutting reseau density and explosive velocity, the radial dispersion angle ofMEFP reduces gradually. Cutting reseau density has not much effect on the radial dispersionangle. but the greater material density is in favour of cut. Section shape of cutting rod has aneffect on cut. Cutting rod can be machined by available manufacturing. High velocitydetonationexplosives should be selected as far as possible under the same length-to-diameterratio of the charge. The liner thickness of coss-shaped MEFP is selected4mm as the best.（2） Contrasted with coss-shaped MEFP, the fragments shape of astroid-shaped MEFP is moreevenly. Rod arc radius of astroid-shaped MEFP is selected40mm as the best.（3）Contrastedwith astroid-shaped MEFP, the shape and aerodynamic of fragments of circle-shaped MEFP ismore evenly. The diameter of ring is selected40～45mm as the best. With the increase ofinitiation point distance, the velocity of fragments increases, the radial dispersion anglereduces gradually. The initiation point distance should be in a proper range from0.56to0.89times as long as Dk(Dkis the charge caliber) in order to form ideal sub-explosively formedprojectile, and it has a best formation and speed at0.78Dk.（4）well-shaped MEFP can formnine fragments with a definite mass and direction. The velocity, distribution area andconvergence of fragments is better. Orthogonal optimization method is applied to analyze theprimary and secondary relations of three factors including cutting reseau distance, rod densityand liner curvature radius influencing the radial dispersion angle of MEFP. The resultsindicate that the curvature radius of the liner is the main influence factor, cutting reseaudistance take the second place, rod density has the minimal impact.（5）The EFP can totallypenetrate30mm steel target. Well-shaped MEFP can totally penetrate10mm steel target,Holes is corresponded to cutting reseau structure. Both rest body of EFP and MEFP havehigher residual velocity. Distribution diameter of MEFP is bigger than that of EFP, whichshows that well-shaped MEFP can improve damage probability for light armored targets suchas helicopter.The research results can provide certain reference for the development of Bar-cuttingMEFP.