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rAKA/extra_packages/extra-materials/src/material_viscoelastic/material_stiffness_proportional.hh
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material_stiffness_proportional.hh
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/**
* @file material_stiffness_proportional.hh
*
* @author David Simon Kammer <david.kammer@epfl.ch>
* @author Nicolas Richart <nicolas.richart@epfl.ch>
*
*
* @brief Material isotropic visco-elastic with viscosity proportional to the
* stiffness
*
* @section LICENSE
*
* Copyright (©) 2010-2012, 2014 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
*/
/* -------------------------------------------------------------------------- */
#include "aka_common.hh"
#include "material.hh"
#include "material_elastic.hh"
/* -------------------------------------------------------------------------- */
#ifndef __AKANTU_MATERIAL_STIFFNESS_PROPORTIONAL_HH__
#define __AKANTU_MATERIAL_STIFFNESS_PROPORTIONAL_HH__
namespace akantu {
/**
* Material visco-elastic @f[\sigma = E\epsilon + \alpha E* \frac{d\epsilon}{dt}@f]
* it can be seen as a Kelvin-Voigt solid with @f[\eta = \alpha E @f]
*
* The material satisfies the Caughey condition, the visco-elastic solid has the
* same eigen-modes as the elastic one. (T.K. Caughey 1960 - Journal of Applied
* Mechanics 27, 269-271. Classical normal modes in damped linear systems.)
*
* parameters in the material files :
* - rho : density (default: 0)
* - E : Young's modulus (default: 0)
* - nu : Poisson's ratio (default: 1/2)
* - Plane_Stress : if 0: plane strain, else: plane stress (default: 0)
* - alpha : viscous ratio
*/
template<UInt spatial_dimension>
class MaterialStiffnessProportional : public MaterialElastic<spatial_dimension> {
/* ------------------------------------------------------------------------ */
/* Constructors/Destructors */
/* ------------------------------------------------------------------------ */
public:
MaterialStiffnessProportional(SolidMechanicsModel & model, const ID & id = "");
virtual ~MaterialStiffnessProportional() {};
/* ------------------------------------------------------------------------ */
/* Methods */
/* ------------------------------------------------------------------------ */
public:
void initMaterial();
/// constitutive law for all element of a type
void computeStress(ElementType el_type, GhostType ghost_type = _not_ghost);
/// compute the potential energy for all elements
virtual void computePotentialEnergy(ElementType el_type, GhostType ghost_type = _not_ghost);
protected:
/// constitutive law for a given quadrature point
//inline void computeStress(Real * F, Real * sigma);
/* ------------------------------------------------------------------------ */
/* Accessors */
/* ------------------------------------------------------------------------ */
public:
/* ------------------------------------------------------------------------ */
/* Class Members */
/* ------------------------------------------------------------------------ */
private:
/// stress due to viscosity
InternalField<Real> stress_viscosity;
/// stress due to elasticity
InternalField<Real> stress_elastic;
/// viscous ratio
Real alpha;
};
/* -------------------------------------------------------------------------- */
/* inline functions */
/* -------------------------------------------------------------------------- */
//#include "material_elastic_caughey_inline_impl.cc"
} // namespace akantu
#endif /* __AKANTU_MATERIAL_STIFFNESS_PROPORTIONAL_HH__ */
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