CentralDifference.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».
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//  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
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//  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: 2005/12/19 22:43:36 $
// $Source: /usr/local/cvs/OpenSees/SRC/analysis/integrator/CentralDifference.h,v $


#ifndef CentralDifference_h
#define CentralDifference_h

// Written: Andreas Schellenberg (andreas.schellenberg@gmx.net) 
// Created: 02/05
// Revision: A
//
// Description: This file contains the class definition for CentralDifference.
// CentralDifference is an algorithmic class for performing a transient analysis
// using the central difference integration scheme.
//
// What: "@(#) CentralDifference.h, revA"

#include "solution/analysis/integrator/transient/RayleighBase.h"
#include "solution/analysis/integrator/transient/ResponseQuantities.h"

namespace XC {
class DOF_Group;
class FE_Element;
class Vector;

//
class CentralDifference: public RayleighBase
  {
  private:
    int updateCount;                // method should only have one update per step
    double c2, c3;                  // some constants we need to keep
    Vector Utm1; 
    ResponseQuantities Ut; 
    ResponseQuantities U; 
  protected:
    int sendData(CommParameters &);
    int recvData(const CommParameters &);

    friend class SoluMethod;
    friend class FEM_ObjectBroker;
    CentralDifference(SoluMethod *);
    CentralDifference(SoluMethod *,const RayleighDampingFactors &rF);
    Integrator *getCopy(void) const;
  public:
    // methods which define what the FE_Element and DOF_Groups add
    // to the system of equation object.
    int formEleTangent(FE_Element *theEle);
    int formNodTangent(DOF_Group *theDof);        
    
    int domainChanged(void);    
    int newStep(double deltaT);    
    int update(const Vector &U);
    int commit(void);
    
    virtual int sendSelf(CommParameters &);
    virtual int recvSelf(const CommParameters &);
    
    void Print(std::ostream &s, int flag = 0);        
  };
inline Integrator *CentralDifference::getCopy(void) const
  { return new CentralDifference(*this); }
} // end of XC namespace

#endif