This project is focused on the development of a software based on the Arlequin multi-model coupling method. The main interest of this software is to allow, by its specific structure, the easy interfacing of different third-party softwares (developed and maintained outside of this project), and adapted to each of the models appearing in the coupling. Currently, this project includes two implementations of the CArl sofware:

1. a MATLAB implementation.
2. a parallel C++ / MPI implementation, based on libMesh and CGAL.

This software is mainly developed at laboratoire MSSMat (Ecole Centrale Paris - CNRS).

• contact : Regis Cottereau
• contributors (by order of first commit): R. Cottereau, C. Zaccardi, Y. Le Guennec, D. Neron, T. M. Schlittler

more detail on installation procedures and examples can be found the related help web page

The MATLAB implementation of the CArl software can be found at the directory MATLAB. Currently, the software to which it is interfaced includes :

1. a 1D/2D FEM acoustic code,
2. a Timoschenko beam code,
3. an elastic code, and
4. Comsol (http://www.comsol.com).

Before using the software, you should make sure that you update the matlab path with the appropriate directories. In matlab, run >> addpath( genpath('install_dir_CArl/')); where you replace install_dir_CArl by the full path to the directory CArl/

Additionally, you might want to write this line in the startup file (located by defaut for instance in MacOS in ~/Documents/MATLAB/startup.m)

This code has not been extensively tested, but should run on Matlab versions R2013a and newer (mainly because the objects triangulation and delaunayTriangulation are required)

To use the option FE2D (optional), one should install and make available in the path the functions downloadable at http://www.mathworks.in/matlabcentral/fileexchange/27826-fast-assembly-of-stiffness-and-matrices-in-finite-element-method (by Talal Rahman and Jan Valdman)

To use the option beam (optional), one should install and make available in the path the functions downloadable at https://github.com/wme7/aero-matlab/tree/master/FEM/Timoshenko_beam (by Manuel Diaz and A Ferreira)

To use the option Comsol (optional), one should install and make available in the path COMSOL Multiphysics (see http://www.comsol.com/)

The main calling routine is CArl.m

Some examples (in 1D and 2D) can be launched through use of the routine Test.m (see the corresponding help). The tests should run without any problem on computers with around 2Go.

The C++ / MPI implementation of the CArl software can be found in the directory Cpp. Currently, it is capable of interfacing with external solvers based on the PETSc toolkit (including the libMesh solvers, when compiled with PETSc support).

The usage of this implementation will be added in the near future, together with a general documentation and examples.

This code implementation use the following third party libraries: (the numbers indicate the oldest version for which they were tested)

1. Boost (version 1.60.0)
2. CGAL (version 4.7)
3. PETSc (version 3.6.2)
4. libMesh (version 1.1.0, installed with TetGen support for now)

The following compiler combinations were tested:

1. OS X / macOS : Clang (version 7.0.0) and OpenMPI (version 1.10.0)
2. Linux : Intel C++ compilers (version 16.0.3) and Intel MPI (version 5.1.2)

This code was not tested or compiled with other operational systems.

The installation is done using CMake (version 3.4.2), and the following commands:

cd [CArl root directory]/Cpp/bin

cmake ..

make

This will compile the CArl software using the default system compilers and with the Release optimization flags (-O3 -DNDEBUG). If you want to change these, use the appropriate flags or an interface such as ccmake or cmake-gui.

The CMake script will search for the Boost and CGAL libraries at the default include paths. For the libMesh installation, it will search for a LIBMESH_DIR environement variable. If the environement variable is not found, it will set it as /usr/local. In both cases, the script will search the libmesh-config binary at the $LIBMESH_DIR/bin directory.

Original references for the theory are (among others)

1. H. Ben Dhia. Multiscale mechanical problems: the Arlequin method, Comptes Rendus de l'Academie des Sciences - Series IIB 326 (1998), pp. 899-904.
2. H. Ben Dhia, G. Rateau. The Arlequin method as a flexible engineering design tool, Int. J. Numer. Meths. Engr. 62 (2005), pp. 1442-1462.

Many other papers make use of the method or describe specific aspects and implementation details. Some of the scientific papers that made use of the CArl software are included in references.rtf