Axisymmetric Adaptive ES-FEM-SPH Coupling Algorithm for Simulating Impact Problems

Impact dynamics problems are ubiquitous in various engineering applications, often involving nonlinear phenomena such as material fracture, damage, and fragmentation. It poses significant challenges to numerical simulation methods. To deal with these challenges, this paper develops an adaptive axisymmetric coupling method that combines the edge-based smoothed finite element method (ES-FEM) with smoothed particle hydrodynamics (SPH), referred to as the ES-FEM-SPH method. Initially, the entire computation employs ES-FEM, which effectively alleviates the excessive stiffness inherent in conventional FEM while maintaining high accuracy, particularly when using linear triangular elements. During the simulation, if any element undergoes severe distortion, the algorithm converts it into an SPH particle and continues the computation with SPH automatically. Thus, it can effectively address issues such as large deformation. To validate the efficacy and reliability of the proposed method, this study performs numerical simulations on several representative cases, including Taylor bar impact, projectile penetration into aluminum plates, and flat-nosed projectile impact on metal target plates. The results demonstrate that the adaptive axisymmetric ES-FEM-SPH coupling method exhibits good performance in both computational accuracy and efficiency, making it well suited for numerical simulations of impact-related problems and holding substantial promise for engineering applications.