Research On Pre-controlled Fragments Processed By SLM

Pre-formed fragment warhead uses the kinetic energy of fragments to damage the target,so how to utilize the pre-controlled fragmentation technology to produce high-speed and effective fragments as much as possible has been the purpose of the pre-formed fragment warhead design.With the emergence of new processing technology,the pre-controlled fragmentation technology has come into a new development.In this paper,the 316L stainless steel shell obtained by SLM technology is used to study the effect of different groove parameters on fragment formation and lethality ability.Firstly,the dynamic mechanical properties of the materials obtained by the Selective Laser Melting(SLM)are studied in this paper so as to provide the parameters of the material constitutive model for the subsequent numerical simulation.Then,a relatively complex internal groove structure is designed to realize the pre-controlled fragmentation,and the feasibility of SLM technology in pre-formed fragment warhead is studied.Numerical simulation is used to study the influence of the depth and angle of internal grooves as well as the size and angle of the grid on the formation and the initial velocity of fragments.It is found that as the depth of V grooves increases the shell is more easily broken,but the speed is smaller,so it is necessary to choose a compromised relative depth to realize the optimization of pre-controlled fragmentation technology.Along with the increase of the axial angle of V groove grid,the crushing effect fragmental deteriorates,when V groove grid angle is too large,pre-controlled fragmentation technology lost meaning,the characteristics of shell is similar to uncontrolled shell.Finally,the feasibility of making pre-formed fragment warhead shell by SLM technology is verified.The formation,initial velocity and the space distribution of fragments as well as the expansion radius of the shell are studied by test(including the crushing test and the static detonation test).It is found that the initial velocity of the fragment decreases with the increase of the groove depth.The fragment space distribution of the pre-formed fragment warhead with the 2mm depth groove is the best.The shape of the fragment is the same,the fragment flying characteristic is close,and the fragment is dispersed along the radius direction relative to the initial position.