VPDependentFriction.h

// -*-c++-*-
//----------------------------------------------------------------------------
//  XC program; finite element analysis code
//  for structural analysis and design.
//
//  Copyright (C)  Luis C. Pérez Tato
//
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//  developed by the  «Pacific earthquake engineering research center».
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//----------------------------------------------------------------------------
/* ****************************************************************** **
**    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.                                               **
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** University of California, Berkeley, is strictly prohibited.  See   **
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**                                                                    **
** Developed by:                                                      **
**   Frank McKenna (fmckenna@ce.berkeley.edu)                         **
**   Gregory L. Fenves (fenves@ce.berkeley.edu)                       **
**   Filip C. Filippou (filippou@ce.berkeley.edu)                     **
**                                                                    **
** ****************************************************************** */

// $Revision: 1.1 $
// $Date: 2009/04/17 23:02:41 $
// $Source: /usr/local/cvs/OpenSees/SRC/element/special/frictionBearing/frictionModel/VPDependentFriction.h,v $

#ifndef VPDependentFriction_h
#define VPDependentFriction_h         

// Written: Andreas Schellenberg (andreas.schellenberg@gmx.net)
// Created: 02/06
// Revision: A
//
// Description: This file contains the class definition for the VPDependentFriction
// friction model after Constantinou et al. (1996). In the velocity and pressure
// dependent friction model the friction force is given in terms of the friction
// coefficients at low and high velocities with the latter one being a function of
// pressure.
//
// What: "@(#) VPDependentFriction.h, revA"

#include "VDependentFriction.h"

namespace XC {
//
class VPDependentFriction: public VDependentFriction
  {
  private:
    double A; 
    double deltaMu; 
    double alpha; 
    inline const double &muFast0(void) const
      { return muFast; }
  protected:
    int sendData(Communicator &);
    int recvData(const Communicator &);
  public:
    // constructor
    VPDependentFriction(void);
    VPDependentFriction(int tag, double muSlow, double muFast0, double A,
        double deltaMu, double alpha, double transRate);
    
    // public methods to set and obtain response
    int setTrial(double normalForce, double velocity = 0.0);
    double getDFFrcDNFrc(void);
    
    FrictionModel *getCopy(void) const;
    
    int sendSelf(Communicator &);
    int recvSelf(const Communicator &);
    
    void Print(std::ostream &s, int flag = 0) const;
  };
} // end of XC namespace

#endif