Adaptivity in CEA’s Fluid Elements in EUROPLEXUS

The present work completes the implementation of adaptivity routines by extending them to CEA’s fluid finite elements both in 2D (TRIA and CAR1) and in 3D (TETR and CUBE). The CAR1 is treated like other 2D quadrilaterals (Q41L, FL24) as far as geometrical issues are concerned. In addition to the solid case, the activation of adaptivity for fluids requires the suitable treatment of transport terms which arise in the Eulerian or ALE forms of the governing equations. For the CEA’s fluid finite elements mentioned above (TRIA, CAR1, TETR and CUBE) this is done in routines tr2me.ff (for the 2D case) and tr3me.ff (for the 3D case), respectively. Therefore, most modifications for the current implementation are concentrated in those two routines. Actually, a special version of the routines is written, valid for the mesh adaptive case.JRC.G.4-European laboratory for structural assessmen

Testing of the GLIS contact model in EUROPLEXUS

This document presents some numerical tests for the verification of the GLIS contact model available (among other contact models) in the EUROPLEXUS code (EPX).JRC.G.4-European laboratory for structural assessmen

Some notes on elasto-plasticity models in Europlexus ancestor codes

These notes are based upon the report by Francois Frey: Le Calcul Elasto-plastique des Structures par le Methode des Elements Finis et son Application a l’Etat Plan de Contrainte. Rapport N. 33, LMMSC, Universite de Liege. July 1973.JRC.G.4-European laboratory for structural assessmen

Adaptivity with Simplex Elements in EUROPLEXUS

This report is a sequel to reports and publications [1-12] on mesh adaptivity in fast transient dynamics and presents the formulation and implementation of mesh adaptivity for simplex elements (triangles in 2D, tetrahedra in 3D) in fast transient dynamics. The algorithms are implemented in the EUROPLEXUS code. EUROPLEXUS [13] is a computer code for fast explicit transient dynamic analysis of fluid-structure systems jointly developed by the French Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA Saclay) and by the Joint Research Centre of the European Commission (JRC Ispra). The present work extends mesh adaptivity to simplex element shapes, i.e. the 3-node triangle (TRI3) in 2D and the 4-node tetrahedron (TET4) in 3D. These elements are useful in fully general unstructured meshing of complex geometries.JRC.G.5-European laboratory for structural assessmen

Simulation of blast waves by using mapping technology in EUROPLEXUS

Finite element or finite volume simulations for the development of blast waves by using a model for the explosion of the solid itself need very fine meshes in the explosive and in the zone around the explosive. Structures may have a long distance to the source of the explosive. This leads often to very big meshes with many elements. The explosive is meshed often only coarse and therefore the results are not very accurate. There are several possibilities to deal with this problem. Large 3D calculations with a solid TNT model using a JWL-equation can be used but they are more effective when the results of one finer mesh could be mapped in a coarser mesh after some calculation steps. When the blast wave reaches a certain distance to the charge, the small elements inside the charge are not needed any more since the pressure ratio is decreased strongly. These small elements results in very small time steps for the full model. The report shows the implementation of the mapping algorithm in EUROPLEXUS and several validation tests of the method.JRC.G.4-European laboratory for structural assessmen

Visualization of Fluid-Structure Interaction Pressure acting on Structures with EUROPLEXUS

This report describes the implementation of a method for the visualization of fluid pressures acting on structures computed by various Fluid-Structure Interaction (FSI) approaches in EUROPLEXUSJRC.G.4-European laboratory for structural assessmen

A solution mapping algorithm in EUROPLEXUS

This report presents the implementation in the EUROPLEXUS code of the possibility of storing a solution for later re-mapping it as initial conditions for a subsequent simulation. EUROPLEXUS [1] (also abbreviated as EPX) is a computer code jointly developed by the French Commissariat a l'Energie Atomique (CEA DMT Saclay) and by EC-JRC. The code application domain is the numerical simulation of fast transient phenomena such as explosions, crashes and impacts in complex three-dimensional uid-structure systems. The Cast3m [2] software from CEA is used as a pre-processor to EPX when it is necessary to generate complex meshes. The interest for a general solution re-mapping algorithm in a code such as EPX is evident, since such an algorithm would allow to perform complex simulations that would be impossible or impractical (e.g. due to high CPU cost) to carry out as a monolithic calculation.JRC.E.4-Safety and Security of Building

Implementation of Flying Debris Fatal Risk Calculation in EUROPLEXUS

This study presents a numerical approach for the calculation of fatality risk caused by the impact of flying debris on the human body. Following an explosion, the formation of a large number of high velocity flying fragments, especially from glass panes, is very possible. The velocity, the mass and the shape of these projectiles define their hazardousness. The developed numerical approach is integrated into fluid-structure interaction techniques, commonly used for the determination of the behaviour of a structure under blast loading. The implementation of the numerical approach in the EUROPLEXUS code is described thoroughly.JRC.G.4 - European laboratory for structural assessmen

Implementation of the LINK DECO RIGI directive under MPI in EUROPLEXUS

This report presents the implementation of the LINK DECO RIGI directive under domain decomposition (MPI version) in EUROPLEXUS.JRC.E.4-Safety and Security of Building

Implementation of Assembled Surface Normals and of a Penalty Contact Formulation in the Pinball Model of EUROPLEXUS - Revision 1

This is a completely revised version of the report "Implementation of Assembled Surface Normals and of a Penalty Contact Formulation in the Pinball Model of EUROPLEXUS", EUR 26714 EN, JRC90939, 2014 [18]. The major changes are: * A different choice of the definition of the contact normal. The old definition was taken from the original work of Belytschko et al. The new definition is opposite to the previous one, to be in accordance with the pre-existing implementation of the pinball contact algorithm without ASN and based on Lagrange multipliers (strong formulation) in EUROPLEXUS and documented in reference [13]. * The fact that for shell/beam/bar elements without a topological thickness the ASN is defined only apart from the sign is now taken into account in the algorithm to compute the contact normal. * The case of contact between two corner pinballs in 3D ( - contact) is now treated by the more accurate expression using the line joining the closest points on the two segments, instead of the generic expression. * The calculation of the ASN for a descendent pinball of shell type in 3D has been revised, as concerns the case of a descendent near a node of shell element. This yields more consistent normals in this case.JRC.E.4-Safety and Security of Building