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00001 /* ****************************************************************** **
00002 **    OpenSees - Open System for Earthquake Engineering Simulation    **
00003 **          Pacific Earthquake Engineering Research Center            **
00004 **                                                                    **
00005 **                                                                    **
00006 ** (C) Copyright 1999, The Regents of the University of California    **
00007 ** All Rights Reserved.                                               **
00008 **                                                                    **
00009 ** Commercial use of this program without express permission of the   **
00010 ** University of California, Berkeley, is strictly prohibited.  See   **
00011 ** file 'COPYRIGHT'  in main directory for information on usage and   **
00012 ** redistribution,  and for a DISCLAIMER OF ALL WARRANTIES.           **
00013 **                                                                    **
00014 ** Developed by:                                                      **
00015 **   Frank McKenna (fmckenna@ce.berkeley.edu)                         **
00016 **   Gregory L. Fenves (fenves@ce.berkeley.edu)                       **
00017 **   Filip C. Filippou (filippou@ce.berkeley.edu)                     **
00018 **                                                                    **
00019 ** ****************************************************************** */
00020                                                                         
00021 // $Revision: 1.3 $
00022 // $Date: 2001/06/14 05:48:28 $
00023 // $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/Steel01.h,v $
00024                                                                         
00025                                                                         
00026 #ifndef Steel01_h
00027 #define Steel01_h
00028 
00029 // File: Steel01.h
00030 //
00031 // Written: MHS 
00032 // Created: 06/99
00033 // Revision: A
00034 //
00035 // Description: This file contains the class definition for 
00036 // Steel01.h
00037 // 
00038 //
00039 //
00040 // What: "@(#) Steel01.h, revA"
00041 
00042 
00043 #include <UniaxialMaterial.h>
00044 
00045 // Default values for isotropic hardening parameters a1, a2, a3, and a4
00046 #define STEEL_01_DEFAULT_A1        0.0
00047 #define STEEL_01_DEFAULT_A2       55.0
00048 #define STEEL_01_DEFAULT_A3        0.0
00049 #define STEEL_01_DEFAULT_A4       55.0
00050 
00066 class Steel01 : public UniaxialMaterial
00067 {
00068   public:
00070     Steel01(int tag, double fy, double E0, double b,
00071 
00072        double a1 = STEEL_01_DEFAULT_A1, double a2 = STEEL_01_DEFAULT_A2,
00073        double a3 = STEEL_01_DEFAULT_A3, double a4 = STEEL_01_DEFAULT_A4,
00074        double min = NEG_INF_STRAIN, double max = POS_INF_STRAIN);
00076     Steel01();
00078     ~Steel01();
00079 
00081     int setTrialStrain(double strain, double strainRate = 0.0); 
00083     int setTrial (double strain, double &stress, double &tangent, double strainRate = 0.0);
00085     double getStrain(void);              
00087     double getStress(void);
00089     double getTangent(void);
00091     double getSecant (void);
00092 
00094     int commitState(void);
00096     int revertToLastCommit(void);    
00098     int revertToStart(void);        
00099 
00101     UniaxialMaterial *getCopy(void);
00102     
00104     int sendSelf(int commitTag, Channel &theChannel);  
00106     int recvSelf(int commitTag, Channel &theChannel, 
00107    FEM_ObjectBroker &theBroker);    
00108     
00110     void Print(ostream &s, int flag =0);
00111     
00113     int setParameter(char **argv, int argc, Information &info);
00115     int updateParameter(int parameterID, Information &info);
00116 
00117   protected:
00118     
00119   private:
00120     /**** Material Properties ***/
00121     double fy;  
00122     double E0;  
00123     double b;   
00124     double a1;
00126     double a2;
00128     double a3;
00130     double a4;  
00131     double epsmin;  
00132     double epsmax;  // Maximum allowable strain
00133 
00134     /**** Calculated Material Properties ***/
00135     double epsy;
00137     double Esh;
00138 
00139     /**** CONVERGED History Variables ***/
00140     double CminStrain;  
00141     double CmaxStrain;  
00142     double CshiftP;     
00143     double CshiftN;     
00144     int Cloading;       // Flag for loading/unloading
00145                         // 1 = loading (positive strain increment)
00146                         // -1 = unloading (negative strain increment)
00148     int Cfailed;        // Flag indicating failure ...  a committed strain
00149                         // has fallen out of the range [epsmin, epsmax]
00150 
00151 
00152     /**** CONVERGED State Variables ***/    
00153     double Cstrain;
00155     double Cstress;
00157     double Ctangent;    
00158 
00159     /**** TRIAL History Variables ***/
00160     double TminStrain;
00162     double TmaxStrain;
00164     double TshiftP;
00166     double TshiftN;
00168     int Tloading;
00170     int Tfailed;
00171     
00172     /**** TRIAL State Variables ***/
00173     double Tstrain;
00175     double Tstress;
00177     double Ttangent; // Not really a state variable, but declared here
00178                      // for convenience
00179 
00181     void setHistoryVariables ();
00182 
00184     void determineTrialState (double dStrain);
00185 
00187     void detectLoadReversal (double dStrain);
00188 };
00189 
00190 #endif