.. _R7.01.49:

**r7.01.44** Behavior Model CSSM
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**Summary:**

.. _OLE_LINK2:

This document presents the formulation and numerical integration of the elastoplastic behavior model CSSM ("Critical State Soil Model"). 
Model CSSM is a combination of two models aimed at representing the monotonic and cyclical drained behavior of soils, respectively. The first component is based on the modified Cam-Clay model [RoBu68] _, 
which describes the phenomena of dilatance or contraction as well as the effects of confinement under monotonous and drained loads. The second component is an Iwan [Iwan66] _ multi-mechanism model, 
designed to represent the cyclical nonlinear behavior of soils at low levels of deformation. 

Behavior model CSSM has a total of eleven parameters: two to describe the reversible (elastic) behavior, five for the irreversible behavior related to the modified Cam-Clay component, and three for the irreversible behavior related to the Iwan component.
A final parameter weighs the contributions of the two components on the shear behavior of model CSSM.

Behavioral equations are solved using an implicit direct time integration method, implemented in tool MFront [HMPS15] _.

.. toctree::
    :numbered:
    :maxdepth: 2
    :caption: User Documentation

    Notations
    Formulation_modele_CSSM
    Parametres_modele_CSSM
    Integration_numerique_modele_CSSM
    Cas_tests_CSSM
    Jacobien_CSSM
    Bibliographie_CSSM