.. _R7.01.38: **r7.01.38** Iwan's law for the cyclic behavior of granular materials ============================================================================== **Summary:** Iwan's behavior model [:ref:`1 `], [:ref:`2 `] is a classical multi-mechanism elastoplastic model for describing the cyclic deviatoric behavior of materials and particularly geomaterials. Work hardening is linear kinematic for each mechanism and the flow rule in question is associated. By construction, the model automatically verifies the Masing rules. The model allows an easy description of the behavior via parameters directly obtained from the curves of variation of the secant shear modulus. The user simply needs to provide the parameters of a hyperbolic function describing the variation of the secant modulus as a function of shear deformation. It is implemented in environment MFront, making it easy to implement and maintain the model. .. toctree:: :hidden: self .. toctree:: :maxdepth: 2 :numbered: Formulation_th_orique Int_gration_num_rique_de_la_loi_de_comportement_ Implantation_dans_code_aster Fonctionnalit_s_et_v_rification Bibliographie