Discrete Particle Method for Simulating Hypervelocity Impact Phenomena

Abstract

In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI) phenomena which is based on the Discrete Element Method (DEM). Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms−1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we use discrete spherical particles that interact with each other via potentials. In our numerical investigations we are particularly interested in the dynamics of material fragmentation upon impact. We model a typical HVI experiment configuration where a sphere strikes a thin plate and investigate the properties of the resulting debris cloud. We provide a quantitative computational analysis of the resulting debris cloud caused by impact and a comprehensive parameter study by varying key parameters of our model. We compare our findings from the simulations with recent HVI experiments performed at our institute. Our findings are that the DEM method leads to very stable, energy–conserving simulations of HVI scenarios that map the experimental setup where a sphere strikes a thin plate at hypervelocity speed. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

“…These materials are assumed to impact at hypervelocities; i.e. velocities high enough that material strength becomes negligible and its behaviour can be described as that of a fluid [51,52].…”

A PD simulation-informed prediction of penetration depth of rigid rods through materials susceptible to microcracking

“…Obviously, in this case, the parameters of the interparticle potential are selected by considering the behavior of the material on macro scale (top-down approach [20]). Watson and Steinhauser [24] recently devised a similar particle potential to model hypervelocity impact of aluminum spheres into a fixed thin plate with a notable difference that, instead of the Born-Mayer potential, a "more ductile" Leonard-Jones 6-12 potential is used in the nonlinear repulsive branch, Eq. (1a).…”

Simulation of Fragmentation Characteristics of Projectile Jacket Made of Tungsten Alloy after Penetrating Metal Target Plate using SPH Method

“…The issue of dynamic fragmentation of solid material under impact loading is a long-term research topic in the fields of elastic-plastic mechanics, dynamic mechanical properties of material, aerospace and weapon science. At present, the main methods to simulate the dynamic fracture of solid material are finite element method (FEM) 2 , discrete element method (DEM) 3 , finite element method combined with discrete element method [4][5] , level set method 6 , molecular dynamics method 7 and smooth particle hydrodynamics (SPH) method [8][9][10] . The finite element method is difficult to display the discontinuity accurately such as crack, for it is difficult to deal with the contact problem of the crack surface and crack propagation on multiple elements 11 .…”

“…The DEM is mostly applied to diverse problems in granular processes such as packing of particles, die filling, fragmentation of agglomerates, bulk compression, powder mixing. Though the DEM method has been applied to shock impact simulations and the fragmentation under shock compression, it is mostly applied to the fragmentation problems of brittle materials such as rock and ceramics 3 . Molecular dynamics is an effective mean to study the microcosmic world, but it is not very suitable to simulate the macroscopic fracture of materials.…”