Overview

MFront comes with an handy easy-to-use tool called MTest that can test the local behaviour of a material, by imposing independent constraints on each component of the strain or the stress. This tool has been much faster (from ten to several hundred times depending on the test case) than using a full-fledged finite element solver. It equivalent to the SIMU_POINT_MAT operator available within the Code-Aster finite element solver (EDF 2013) or to the SiDoLo software (Pilvin 2003).

MTest can be used to model various experiments, as far as a stage implying strain localisation is not reached: tensile, compressive or shear tests driven by stresses or deformations, pipe loaded by internal or external pressure, test, etc.

MTest generates a text file containing the evolution of the strains (for small strains behaviours), the stresses an the state variables during the loading history. Other MTest functionalities include:

Through an appropriate option, a behaviour implementation generated through MFront may create an MTest file in case of integration failure: this MTest file only describe the failed time step with the appropriate initial conditions. This feature is particularly useful to analyse the failure of large simulations which may happen after several hours of computations.

Example

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@Behaviour<aster> 'src/libAsterBehaviour.so' 'asterplasticity';
@MaterialProperty<constant> 'YoungModulus'     150.e9;
@MaterialProperty<constant> 'PoissonRatio'       0.3;
@MaterialProperty<constant> 'H'                100.e9;
@MaterialProperty<constant> 's0'               100.e6;
@ExternalStateVariable 'Temperature' {0:293.15,3600.:800};
@ImposedStrain<function> 'EXX' '1.e-3*t';
@Times {0.,1 in 20};

References

EDF. 2013. “Macro-Commande SIMU_POINT_MAT.” Référence du Code Aster U4.51.12 révision 9069. EDF-R&D/AMA. http://www.code-aster.org.

Pilvin, P. 2003. “SiDoLo Version 2.4495.” Notice d’utilisation. Laboratoire Génie Mécanique et Matériaux, Université de Bretagne Sud.

Salome. 2014a. “ADAO, a SALOME Module for Data Assimilation and Optimization.” http://www.salome-platform.org/.

———. 2014b. “The Open Source Integration Platform for Numerical Simulation.” http://www.salome-platform.org/.

Von Rossum, G. 2007. “Python Library Reference.” http://docs.python.org.