DruckerPrager.h

//----------------------------------------------------------------------------
//  XC program; finite element analysis code
//  for structural analysis and design.
//
//  Copyright (C)  Luis Claudio Pérez Tato
//
//  This program derives from OpenSees <http://opensees.berkeley.edu>
//  developed by the  «Pacific earthquake engineering research center».
//
//  Except for the restrictions that may arise from the copyright
//  of the original program (see copyright_opensees.txt)
//  XC is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or 
//  (at your option) any later version.
//
//  This software is distributed in the hope that it will be useful, but 
//  WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details. 
//
//
// You should have received a copy of the GNU General Public License 
// along with this program.
// If not, see <http://www.gnu.org/licenses/>.
/* ****************************************************************** **
**    OpenSees - Open System for Earthquake Engineering Simulation    **
**          Pacific Earthquake Engineering Research Center            **
**                                                                    **
**                                                                    **
** (C) Copyright 1999, The Regents of the University of California    **
** All Rights Reserved.                                               **
**                                                                    **
** Commercial use of this program without express permission of the   **
** University of California, Berkeley, is strictly prohibited.  See   **
** file 'COPYRIGHT'  in main directory for information on usage and   **
** redistribution,  and for a DISCLAIMER OF ALL WARRANTIES.           **
**                                                                    **
** Developed by:                                                      **
**   Frank McKenna (fmckenna@ce.berkeley.edu)                         **
**   Gregory L. Fenves (fenves@ce.berkeley.edu)                       **
**   Filip C. Filippou (filippou@ce.berkeley.edu)                     **
**                                                                    **
**                                                                    **
**                                                                    **
**                                                                    **
** ****************************************************************** */

#ifndef DruckerPrager_h
#define DruckerPrager_h

// $Revision: 1.1 $
// $Date: 2010-02-04 00:44:04 $
// $Source: /usr/local/cvs/OpenSees/SRC/material/nD/DruckerPrager.h,v $
                                                                      
// Written: Kathryn Petek, Peter Mackenzie-Helnwein, and Pedro Arduino
// Created: 12/04
//
// Description: This file contains the class definition for DruckerPrager. 
//

#include <material/nD/NDMaterial.h>
#include <utility/matrix/Vector.h>
#include <utility/matrix/Matrix.h>


namespace XC {
//
//
//
class DruckerPrager : public NDMaterial
  {
 protected:
  
  //material parameters
  double mKref;         // reference Bulk Modulus 
  double mGref;         // reference Shear Modulus
  double mPatm;         // reference stress first invariant (pressure)
  double mK;            // bulk modulus 
  double mG;            // shear modulus
  double msigma_y;      // yield strength 
  double mrho;          // volumetric term
  double mrho_bar;      // nonassociative flow term
  double mKinf;         // nonlinear isotropic hardening term
  double mKo;           // nonlinear isotropic hardening term
  double mdelta1;       // exponential hardening term for drucker prager surface
  double mdelta2;       // exponential hardening term for tension cutoff surface
  double mHard;         // hardening constant
  double mtheta;        // hardening constant
  double mTo;           // initial tension cutoff strength

  double massDen;
  
  //internal variables
  Vector mEpsilon;
  Vector mEpsilon_n_p;  // plastic strain vector at step n, trail e_p
  Vector mEpsilon_n1_p; // plastic strain vector at step n+1 
  Vector mSigma;
  
  Vector mBeta_n;       // backstress at step n, beta_np1_trial = beta_n
  Vector mBeta_n1;      // backstress at step n+1
  
  double mHprime;       // derivative of linear kinematic hardening term 
  
  double mAlpha1_n;     // alpha1_n
  double mAlpha1_n1;    // alpha1_n+1
  double mAlpha2_n;     // alpha2_n
  double mAlpha2_n1;    // alpha2_n+1
  
  int mElastFlag;    // Flag to determine elastic behavior
  int mFlag;
  
  Matrix mCe;           // elastic tangent stiffness matrix
  Matrix mCep;          // elastoplastic tangent stiffness matrix
  Vector mI1;           // 2nd Order Identity Tensor    
  Matrix mIIvol;        // IIvol = I1 tensor I1  
  Matrix mIIdev;        // 4th Order Deviatoric Tensor
  
  Vector mState;        // state vector for output
  
  //functions
  void initialize();    // initializes variables
  int  updateElasticParam(void); //updated Elastic Parameters based on mean stress 
  
  //plasticity integration routine
  void plastic_integrator(void);
  
  double Kiso(double alpha1);       // isotropic hardening functon
  double Kisoprime(double alpha1);  //
  double T(double alpha2);
  double deltaH(double dGamma);
  
  Vector getState();        // fills vector of state variables for output
  
  //parameters
  static const double one3 ;
  static const double two3 ;
  static const double root23 ;
  public:
    // Full Constructor
    DruckerPrager(int tag, int classTag, double bulk, double shear,
          double s_y, double r, double r_bar, double Kinfinity, double Kinit, 
          double d1, double d2, double H, double t, double massDen = 0.0, double atm = 101.0);

  // Elastic Constructor
  //      DruckerPrager(int tag, double bulk, double shear);
  
  //Null Constructor
  DruckerPrager();
  
  //Destructor
  ~DruckerPrager();
  
  NDMaterial *getCopy(const std::string &type) const;
  
  int commitState(void);
  int revertToLastCommit(void);
  int revertToStart(void);
  
  NDMaterial *getCopy(void) const;
  const std::string &getType(void) const;
  int getOrder(void) const;
  
  Response *setResponse(const std::vector<std::string> &argv, Information &matInfo);
  int getResponse (int responseID, Information &matInformation);
  
  int sendSelf(CommParameters &);  
  int recvSelf(const CommParameters &); 
  
  void Print(std::ostream &, int flag =0);

//int setParameter(const std::vector<std::string> &argv, Parameter &param);
//int updateParameter (int parameterID, Information &info);

  double getRho(void) {return massDen;};
  
};
} // end XC namespace


#endif