J2ThreeDimensional.h

//----------------------------------------------------------------------------
//  XC program; finite element analysis code
//  for structural analysis and design.
//
//  Copyright (C)  Luis Claudio Pérez Tato
//
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//  developed by the  «Pacific earthquake engineering research center».
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// along with this program.
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//----------------------------------------------------------------------------
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**    OpenSees - Open System for Earthquake Engineering Simulation    **
**          Pacific Earthquake Engineering Research Center            **
**                                                                    **
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** (C) Copyright 1999, The Regents of the University of California    **
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// $Revision: 1.5 $
// $Date: 2003/02/14 23:01:25 $
// $Source: /usr/local/cvs/OpenSees/SRC/material/nD/J2ThreeDimensional.h,v $

// Written: Ed "C++" Love

//
// J2ThreeDimensional isotropic hardening material class
// 
//  Elastic Model
//  sigma = K*trace(epsilion_elastic) + (2*G)*dev(epsilon_elastic)
//
//  Yield Function
//  phi(sigma,q) = || dev(sigma) ||  - sqrt(2/3)*q(xi) 
//
//  Saturation Isotropic Hardening with linear term
//  q(xi) = simga_0 + (sigma_infty - sigma_0)*exp(-delta*xi) + H*xi 
//
//  Flow Rules
//  \dot{epsilon_p} =  gamma * d_phi/d_sigma
//  \dot{xi}        = -gamma * d_phi/d_q 
//
//  Linear Viscosity 
//  gamma = phi / eta  ( if phi > 0 ) 
//
//  Backward Euler Integration Routine 
//  Yield condition enforced at time n+1 
//
//  Send strains in following format :
// 
//     strain_vec = {   eps_00
//                      eps_11
//                  eps_22            
//                    2 eps_01   
//                    2 eps_12   
//            2 eps_20    }   <--- note the 2
// 
//  set eta := 0 for rate independent case
//

#ifndef J2THREEDIMENSIONAL_H
#define J2THREEDIMENSIONAL_H

#include "material/nD/J2Plasticity.h"

namespace XC{
//
class J2ThreeDimensional : public J2Plasticity {

//-------------------Declarations-------------------------------

  public : 

  J2ThreeDimensional(int tag);

 //null constructor
  J2ThreeDimensional( );

  //full constructor
  J2ThreeDimensional(   int    tag, 
                   double K,
                   double G,
                   double yield0,
                   double yield_infty,
                   double d,
                   double H,
                   double viscosity = 0 );


  //elastic constructor
  J2ThreeDimensional( int tag, double K, double G );

  //make a clone of this material
  NDMaterial* getCopy(void) const;

  //send back type of material
  const std::string &getType( ) const ;

  //send back order of strain in vector form
  int getOrder( ) const ;

  //get the strain and integrate plasticity equations
  int setTrialStrain( const Vector &strain_from_element);

  //unused trial strain functions
  int setTrialStrain( const Vector &v, const Vector &r );
  int setTrialStrainIncr( const Vector &v );
  int setTrialStrainIncr( const Vector &v, const Vector &r );

  //send back the strain
  const Vector& getStrain(void) const;

  //send back the stress 
  const Vector& getStress(void) const;

  //send back the tangent 
  const Matrix& getTangent(void) const;
  const Matrix& getInitialTangent(void) const;

  //this is mike's problem
  int setTrialStrain(const Tensor &v);
  int setTrialStrain(const Tensor &v, const Tensor &r);    
  int setTrialStrainIncr(const Tensor &v);
  int setTrialStrainIncr(const Tensor &v, const Tensor &r);
  const Tensor& getTangentTensor(void) const;
//jeremic@ucdavis.edu 22jan2001  const Tensor& getStressTensor( );
//jeremic@ucdavis.edu 22jan2001  const Tensor& getStrainTensor( );  

  private :

  //static vectors and matrices
  static Vector strain_vec ;     //strain in vector notation
  static Vector stress_vec ;     //stress in vector notation
  static Matrix tangent_matrix ; //material tangent in matrix notation

} ; //end of J2ThreeDimensional declarations


} //end of XC namespace

#endif