Lagrangian approach embed with discrete element method for extreme deformation study in frangible bullet designs fragmentation and penetration on viscoelastic ballistic gel

Development of a model for analyzing a bullet's impact is important in the military field to design a bullet with desired properties. This study uses a finite element model with a Lagrangian framework and Lagrange-discrete element method (DEM) model by ANSYS Explicit Dynamic to investigate the effect of frangible bullet designs on bullet deformation and penetration in ballistic gel setting. A modeling approach with ballistic gel can analyzed the extreme deformation of bullets much faster compared to the more resource intensive real life ballistic gel test. The study starts with developing a 3D model, then importing it to an ANSYS workbench to solve the problems. Overall, the results of Lagrange-DEM shows deeper penetration and better accuracy to represent the real life ballistic gel test than other simulation method. The fluted bullet design has a shorter penetration depth but a bigger temporary cavity diameter than the flat-nosed one due to its notch and asymmetrical design, which becomes the part that is easily deformed and leads to directional deformation.