ViscousMaterial.h

// -*-c++-*-
//----------------------------------------------------------------------------
//  XC program; finite element analysis code
//  for structural analysis and design.
//
//  Copyright (C)  Luis C. 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: 2003/02/14 23:01:40 $
// $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/ViscousMaterial.h,v $
                                                                        
// Written: Mehrdad Sasani 
// Created: June 2000
// Revision: A
//
// Description: This file contains the class interface for 
// ViscousMaterial.  ViscousMaterial defines a force(F)-velocity(v)
// relationship of the form F = C*pow(v,a), where C is a prescribed
// constant and a is a real number.

#ifndef ViscousMaterial_h
#define ViscousMaterial_h

#include <material/uniaxial/UniaxialMaterial.h>

namespace XC {
//
class ViscousMaterial: public UniaxialMaterial
  {
  private:
    double trialRate;
    double C; 
    double Alpha; 
  protected:
    int sendData(Communicator &);
    int recvData(const Communicator &);
  public:
    ViscousMaterial(int tag= 0, double C= 0.0, double Alpha= 1.0);

    void setDampingCoeff(const double &);
    double getDampingCoeff(void) const;
    void setAlpha(const double &);
    double getAlpha(void) const;

    int setTrialStrain(double velocity, double strainRate = 0.0); 
    double getStrain(void) const; 
    double getStrainRate(void) const;
    double getStress(void) const;
    double getTangent(void) const;
    double getInitialTangent(void) const;
    double getDampTangent(void) const;


    int commitState(void);
    int revertToLastCommit(void);    
    int revertToStart(void);        

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


#endif