is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: https://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/17030 To cite this version : Alexia BRAUER, Angelo IOLLO, Thomas MILCENT -A Cartesian scheme for compressible multimaterial models in 3D. 2016-02-17. Brevet n° 121-143Any correspondence concerning this service should be sent to the repository Administrator : archiveouverte@ensam.eu a r t i c l e i n f o a b s t r a c tWe model the three-dimensional interaction of compressible materials separated by sharp interfaces. We simulate fluid and hyperelastic solid flows in a fully Eulerian framework. The scheme is the same for all materials and can handle large deformations and frictionless contacts. Necessary conditions for hyperbolicity of the hyperelastic neohookean model in three dimensions are proved thanks to an explicit computation of the characteristic speeds. We present stiff multimaterial interactions including air-helium and water-air shock interactions, projectile-shield impacts in air and rebounds.

Summary This work presents a level‐set–based sharp interface technique to simulate the evolution of damage in ductile materials under high velocity impact conditions. The level‐set method is adopted to track all interfaces including damage zones within the materials. Two types of damage are considered, ie, the creation of spall zones due to damage accumulation in homogeneous ductile materials and interfacial debonding in heterogeneous materials. Spall is simulated using continuum damage models and a level‐set–based crack generation and evolution algorithm. Three continuum damage models are tested for metal targets subjected to flyer impact; the results from the current code (SCIMITAR3D) are compared with the two widely used computer codes EPIC and CTH, and to experimental data; it is found that the computer codes are in good agreement among each other, but agreement of all methods with experimental data is not uniform. At material interfaces, damage is handled using a cohesive zone model and evolving level sets to create void spaces because of material separation due to debonding. Finally, ductile damage combined with debonding is simulated in an Al‐Ni laminate impacted by a projectile. The results demonstrate the ability of the present approach to simulate various types of damage in materials with heterogeneities and inclusions.

We describe a numerical model to simulate the non-linear elasto-plastic dynamics of compressible materials. The model is fully Eulerian and it is discretized on a fixed Cartesian mesh. The hyperelastic constitutive law considered is neohookean and the plasticity model is based on a multiplicative decomposition of the inverse deformation tensor. The model is thermodynamically consistent and it is shown to be stable in the sense that the norm of the deviatoric stress tensor beyond yield is non increasing. The multimaterial integration scheme is based on a simple numerical flux function that keeps the interfaces sharp. Numerical illustrations in one to three space dimensions of high-speed multimaterial impacts in air are presented.