Computational Efficiency Improvements in Cylindrical SPH Analysis of Hypervelocity Impacts

Numerical simulations of solid-solid hypervelocity impacts (HVIs) using smoothed particle hydrodynamics (SPH) method in two-dimensional axisymmetric coordinates, are performed. It is known that Gaussian kernel is adequate for the SPH method in axisymmetric coordinates, however, Gaussian kernel is computationally less efficient because of its infinite range. We propose to adopt a simple function having only even-order terms as the kernel for the SPH method in axisymmetric coordintates, to improve the computational efficiency. The equations of conservation laws, the strain rate and rotation rate are formulated by using the quadric kernel and the quartic kernel. The HVIs are numerically simulated by using the quadric kernel, quartic kernel and Gaussian kernel for comparison. Each numerical result shows a good agreement with the experimental result, and the conservation of energy is assured for each calculation. Consequently, it is found that the quadric kernel and the quartic kernel have far better computational efficiency and comparable computational accuracy to Gaussian kernel.