Numerical and Experimental Investigation of SPH, SPG and FEM for High Velocity Impact Applications

During a high-velocity impact event large pressure, strain rate, and deformation occur. This is a very demanding scenario for mesh-based approaches like the FEM (Finite Element Method). In particular, for the description of fracture, special techniques like erosion or node splitting are required. For a comprehensive validation, we have designed a projectile surrogate and conducted impact experiments at different oblique angles in our laboratories. These experiments are observed with X-ray cinematography and physical properties for validation are extracted from the images. For the highly dynamic behavior during the impact, an alternative to mesh-based approaches are particle-based methods. LS-DYNA® offers two pure particle methods, SPH (Smooth Particle Hydrodynamics) and SPG (Smooth Particle Galerkin). This study compares SPH to the FEM results and the experimental data. Since the discretization requirements for the numerical approaches are different, it is not possible to compare exactly the same discretization. Instead, the number of nodes is chosen similarly. The accuracy is investigated qualitatively, using X-ray images, as well as quantitatively, using the extracted properties from the experiments.