Pinching.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)                     **
**                                                                    **
** ****************************************************************** */
                                                                        
// $Revision: 1.4 $
// $Date: 2004/09/01 03:53:13 $
// $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/snap/Pinching.h,v $
//
//
// Pinching.h: implementation of the Pinching class from Fortran version.
// Originally from SNAP PROGRAM by Prof H.K. Krawinkler
//
// Written: Arash Altoontash, Gregory Deierlein, 12/01
// Revised: 05/03
//
// Purpose: This file contains the implementation for the Pinching class.
//

// Pinching.h: interface for the Pinching class.
//

#ifndef PINCHING_H
#define PINCHING_H

#include <material/uniaxial/UniaxialMaterial.h>
#include <utility/matrix/Vector.h>
#include <stdio.h>

namespace XC {
//
class Pinching : public UniaxialMaterial  
{
 protected:
  void envelPosCap(double fy, double alfaPos, double alfaCap,
           double cpDsp, double d, double *f, double *ek );
  
  void envelNegCap(double fy, double alfaNeg, double alfaCap,
           double cpDsp, double d, double *f, double *ek);
  
  void recordInfo(int cond =0);
  
  
 private:
  
  // Input parameters
  double elstk,fyieldPos,fyieldNeg,alpha,Resfac; // Properties
  double capSlope,capDispPos,capDispNeg;     // Cap
  double ecaps,ecapk,ecapa,ecapd,cs,ck,ca,cd;    // Degradation parameters
  double fpPos,fpNeg,a_pinch;                    // Pinching
  
  // Parameters calculated from input data
  double dyieldPos,dyieldNeg,Enrgts,Enrgta,Enrgtk,Enrgtd;
  
  double hsTrial[22], hsCommit[22], hsLastCommit[22];
  
  FILE *OutputFile;     // For debugging
 public:
  Pinching();
  Pinching(int tag);
  Pinching(int tag, Vector inputParam );
  virtual ~Pinching();
  
  int setTrialStrain(double d, double strainRate = 0.0);

  double getStrain(void) const;
  double getStress(void) const;
  double getTangent(void) const;
  double getInitialTangent(void) const;

  int commitState(void);
  int revertToLastCommit(void);    
  int revertToStart(void);  
  
  //virtual
  UniaxialMaterial *getCopy(void) const;
  
  int sendSelf(CommParameters &);  
  int recvSelf(const CommParameters &);    
  
  void Print(std::ostream &s, int flag =0);
  
};
} // end of XC namespace

#endif