BarSlipMaterial.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: 1.2 $
// $Date: 2004/10/06 19:21:12 $
// $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/BarSlipMaterial.h,v $
                                                                        
                                                                        
// Written: NM (nmitra@u.washington.edu) 
// Created: January 2002
// Updated: September 2004
//
// Description: This file contains the class defination for 
// bar-slip material. The file generates the 4 point envelope for both positive 
// and negative loading and is basically a wrapper for the Pinching4 material at it's outset.
// Updates: new damage analysis and user interface.


#ifndef BarSlipMaterial_h
#define BarSlipMaterial_h

#include <material/uniaxial/UniaxialMaterial.h>
//#include <material/uniaxial/Pinching4Material.h>
#include <cmath>
#include <utility/matrix/Matrix.h>
#include <utility/matrix/Vector.h>
#include <utility/handler/FileStream.h>

namespace XC {
//
class BarSlipMaterial : public UniaxialMaterial
  {
  private:
    int tagMat;
    // bond strength flag
    int bsflag;   // 1 --- weak or 0 --- strong bond strength

    // unit used
    int unit;     // 1 --- mpa or 2 --- psi (the coefficients of shear stress will change accordingly)

    // type of j to be used for beam top barslip it is "1" or it is "0" for beam bottom bar slip or column
    int type;

    int damage; // type of damage in the material;

    // dimensions
    double width;  // width of the member
    double depth;  // depth of the member

    // material used at onset
//  Pinching4Material* material;
    Vector envlpPosStress; Vector envlpPosStrain; 
    Vector envlpNegStress; Vector envlpNegStrain;


    // concrete properties
    double fc;   // compressive strength of concrete
    
    // steel properties
    double fy;    // yeild strength of steel
    double Es;    // modulus of elasticity of steel
    double fu;    // ultimate strength of steel
    double Eh;    // modulus of hardening of steel
    double db;    // reinforcing steel bar diameter
    int nbars;  // no of reinforcing bars

    // anchorage length
    double ld;  // anchorage length of the reinforcing steel

        // bond strengths
    double tauET;  // bond strength of steel that is elastic and carries tensile load
    double tauYT;  // bond strength of steel that has yeilded in tension
    double tauEC;  // bond strength of steel that is elastic and carries compression load
    double tauYC;  // bond strength of steel that has yeilded in compression
    double tauR;   // residual bond strength of steel

    // unloading-reloading parameters 
    double rDispP; double rForceP; double uForceP;
    double rDispN; double rForceN; double uForceN;

    // Damage parameters
    double gammaK1; double gammaK2; double gammaK3; double gammaK4; double gammaKLimit;
    double gammaD1; double gammaD2; double gammaD3; double gammaD4; double gammaDLimit;
    double gammaF1; double gammaF2; double gammaF3; double gammaF4; double gammaFLimit;
    double gammaE;


    // positive and negative envelopes
    Matrix eP;
    Matrix eN;

    //**************************************************************************
    // Trial Set varables
    double Tstrain; double Ttangent; double Tstress;

    // Converged Material History parameters
    int Cstate;
    double Cstrain;
    double Cstress;
    double CstrainRate;
    double lowCstateStrain;
    double lowCstateStress;
    double hghCstateStrain;
    double hghCstateStress;
    double CminStrainDmnd;
    double CmaxStrainDmnd;
    double Cenergy;
    double CgammaK;
    double CgammaD;
    double CgammaF;
    double gammaKUsed;
    double gammaFUsed;

    // Trial Material History Parameters
    int Tstate;
    double dstrain;
    double TstrainRate;
    double lowTstateStrain;
    double lowTstateStress;
    double hghTstateStrain;
    double hghTstateStress;
    double TminStrainDmnd;
    double TmaxStrainDmnd;
    double Tenergy;
    double TgammaK;
    double TgammaD;
    double TgammaF;

    // strength and stiffness parameters;
    double kElasticPos;
    double kElasticNeg;
    double kElasticPosDamgd;
    double kElasticNegDamgd;
    double uMaxDamgd;
    double uMinDamgd;

    Vector envlpPosDamgdStress; Vector envlpNegDamgdStress;

    double kunload;
    Vector state3Stress; Vector state3Strain; Vector state4Stress; Vector state4Strain;
    double elasticStrainEnergy;
    double energyCapacity;
//****************************************************************

    void getBondStrength(void);
    void getBarSlipEnvelope(void);
    void createMaterial(void);

    void SetEnvelope(void);
    void getstate(double, double);
    double posEnvlpStress(double);
    double posEnvlpTangent(double);
    double negEnvlpStress(double);
    double negEnvlpTangent(double);

    void getState3(Vector& , Vector& , double);
    void getState4(Vector& , Vector& , double);
    double Envlp3Tangent(Vector , Vector , double);
    double Envlp3Stress(Vector , Vector , double);
    double Envlp4Tangent(Vector , Vector , double);
    double Envlp4Stress(Vector , Vector , double);

    void updateDmg(double);

//FileStream* fn;
//FileStream* fg;
  public :
    BarSlipMaterial(int tag,
        double fc, double fy, double Es, double fu,
        double Eh, double db, double ld, int nbars, double width, double depth,
        int bsflag, int type);

    BarSlipMaterial(int tag,
        double fc, double fy, double Es, double fu,
        double Eh, double db, double ld, int nbars, double width, double depth,
        int bsflag, int type, int damage, int unit);

    BarSlipMaterial(int tag);
    BarSlipMaterial();

    int setTrialStrain(double strain, 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);

    UniaxialMaterial *getCopy(void) const;

    int sendSelf(CommParameters &);
    int recvSelf(const CommParameters &);

    void Print(std::ostream &s, int flag = 0);
  };
} // end of XC namespace
#endif