An Accurate SPH Scheme for Dynamic Fragmentation modelling

Abstract

We focus on the use of a meshless numerical method called Smooth Particle Hydrodynamics (SPH), to solve fragmentation issues as Hyper Velocity Impact (HVI) cases. Firstly applied to fluid flow simulations, this method can be extended to the solid dynamics framework. However it suffers from a lack of accuracy when evaluating state variables as the pressure field. And such inaccuracy generally generates non-physical processes (as numerical fragmentation). In the hydrodynamic context, SPH-ALE methods based on Riemann solvers significantly improve this evaluation, but increase the scheme complexity and low-Mach issues are difficult to prevent. We propose an alternative scheme called γ-SPH-ALE, firstly implemented to solve multi-regime barotropic flows, and secondly extended to solid dynamic cases. It relies on the combination of the SPH-ALE formalism and a finite volume stabilizing low-Mach scheme. Its characteristics are detailed and evaluated through a nonlinear stability analysis, highlighting CFL-like conditions on the scheme parameters. Finally, its implementation on several test cases reveals that the proposed scheme actually increases both stability and accuracy, in reduced computation time, with respect to classical solvers.

Innovative meshless approach for shaped charges applications

“…We refer to [7] for the detailed proof in the context of monophasic barotropic Euler equations. These properties are validated on numerous academic test cases going from hydrodynamics to solid dynamics [7,10]. γ-SPH-ALE is also fully implemented in the Impetus Afea Solver® benefiting from massive GPU parallelization allowing it to provide such compelling results 100 times faster than legacy SPH solvers.…”

“…The combination of the SPH-ALE formalism [8] and a finite volume low-Mach scheme [9] provides consistent and robust stabilization to well-known SPH instabilities such as spurious oscillations and tensile instability. Benefiting from a massively parallelGPU implementation, it provides convincing and reliable results on numerous academic test cases going from hydrodynamics [7] to solid dynamics [10] in reduced computation times contrary to legacy SPH solvers. Thus, we propose to evaluate its capabilities regarding shaped charge modeling.…”

Mechanics of the Tricuspid Valve—From Clinical Diagnosis/Treatment, In-Vivo and In-Vitro Investigations, to Patient-Specific Biomechanical Modeling

“…Constitutive model forms and parameters previously described by Khoiy et al (2018) [108] and Toma et al (2016) [188] were adopted to describe the material properties of the TV leaflets and chordae, respectively. A smooth particle hydrodynamics (SPH) approach [189,190,191,192] rather than the typical FE method under the immersed boundary [193,194,195] or arbitrary Lagrangian-Eulerian [161,196] formulations was employed for modeling the fluid subproblem. This choice was primarily due to the ability of SPH to more accurately capture the separation of flow throughout valve closure and the relatively quick simulation completion time compared to the typical mesh-based methods.…”

Kinetic Energy Penetrator (KEP) impact on confined concrete

“…All the specimens of the study have been manufactured from the same batch. The concrete is modelled with recent type of meshless method called γ-SPH that reveals its efficiency in fragmentation and hypervelocity impacts [2]. This paper shows some preliminary results for a ballistic non-perforating impact and its simulation.…”