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

Numerical Simulations in Support of the Blast Actuator Development Part II

The development of the blast actuator experimental device is now entering the second phase, where reinforced concrete beams are used as specimens. This demanding phase needs a lot of support from numerical simulation to both predict and resolve possible failures and to validate the test results. The current report presents the comparison between the experimental and numerical results, focusing on the justification of the appearing discrepancies. Moreover, interesting information, that can ameliorate the final configuration of the apparatus, is extracted after the interpretation of the numerical results.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

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

Review on vehicle barrier protection guidance

A search and review of publicly available documents with guidance on the security of designated spaces against vehicle-ramming attacks has been conducted. The current report provides a list of these sources, which focus on the protection of public spaces, such as pedestrian areas, tourist sites, city squares or other perimeter protected areas. The list aims at bringing to the interested security stakeholders information on measures to prevent potential attacks and/or mitigate their consequences by properly designed and tested barrier systems.JRC.E.4-Safety and Security of Building

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

Review on Soft target/Public space protection guidance

The current document provides a list of the available information sources focusing on the protection of soft targets against terrorist and other types of malicious extremist attacks. The list aims at bringing to the interested security stakeholder existing documents with information and practical guidance on measures to prevent a potential attack and to mitigate the consequences, should such an attack materializes. The collected documents do not address critical infrastructure, but they mainly focus on the so-called soft targets, the term being used to represent vulnerable material or human assets, which in principle should not be specifically protected. However, such targets are often selected by terrorists in their effort to maximize casualties, inflict fear to the population and attain media coverage. The documents are grouped according to the following broad domains relating to soft targets: public places, education/religious/health installations, transport, building facades, urban resilience, security planning & risk management, policy/regulation/finance, people involvement, and drones. The referenced information sources originate from various countries and bodies, such as UK, France, Sweden, Czech Republic, USA, Australia etc. The list is quite comprehensive but it is limited to the publicly available documents and practically to those found in English and French.JRC.E.4-Safety and Security of Building

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