Quick Links Home Download Documentation Message Board Source Code Class Interface Bugs Tasks Search

Steel01.cpp Go to the documentation of this file. /* ****************************************************************** ** ** 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: 2001/06/14 05:48:28 $ // $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/Steel01.cpp,v $ // File: ~/material/Steel01.C // // Written: MHS // Created: 06/99 // Revision: A // // Description: This file contains the class implementation for // Steel01. // // What: "@(#) Steel01.C, revA" #include <Steel01.h> #include <Vector.h> #include <Channel.h> #include <Information.h> #include <math.h> #include <float.h> Steel01::Steel01 (int tag, double FY, double E, double B, double A1, double A2, double A3, double A4, double min, double max) : UniaxialMaterial(tag,MAT_TAG_Steel01), fy(FY), E0(E), b(B), a1(A1), a2(A2), a3(A3), a4(A4), epsmin(min), epsmax(max) { // Calculated material parameters epsy = fy/E0; // Yield strain Esh = b*E0; // Hardening modulus // Sets all history and state variables to initial values revertToStart (); // Initial stiffness Ttangent = E0; } Steel01::Steel01():UniaxialMaterial(0,MAT_TAG_Steel01), fy(0.0), E0(0.0), b(0.0), a1(0.0), a2(0.0), a3(0.0), a4(0.0), epsmin(0.0), epsmax(0.0) { } Steel01::~Steel01 () { // Does nothing } void Steel01::setHistoryVariables () { TminStrain = CminStrain; TmaxStrain = CmaxStrain; TshiftP = CshiftP; TshiftN = CshiftN; Tloading = Cloading; Tfailed = Cfailed; } int Steel01::setTrialStrain (double strain, double strainRate) { // Reset history variables to last converged state setHistoryVariables (); // Set trial strain Tstrain = strain; // Determine change in strain from last converged state double dStrain = Tstrain - Cstrain; // Calculate the trial state given the trial strain if (fabs(dStrain) > DBL_EPSILON) determineTrialState (dStrain); return 0; } int Steel01::setTrial (double strain, double &stress, double &tangent, double strainRate) { // Reset history variables to last converged state setHistoryVariables (); // Set trial strain Tstrain = strain; // Determine change in strain from last converged state double dStrain = Tstrain - Cstrain; // Calculate the trial state given the trial strain if (fabs(dStrain) > DBL_EPSILON) determineTrialState (dStrain); stress = Tstress; tangent = Ttangent; return 0; } void Steel01::determineTrialState (double dStrain) { if (Tstrain <= epsmin || Tstrain >= epsmax) Tfailed = 1; if (Tfailed) { Tstress = 0.0; Ttangent = 0.0; } else { double c, c1, c2, c3; c = Cstress + E0*dStrain; double fyOneMinusB = fy * (1.0 - b); c1 = Esh*Tstrain; c2 = TshiftN*fyOneMinusB; c3 = TshiftP*fyOneMinusB; double c1c3 = c1+c3; if (c1c3 < c) Tstress = c1c3; else Tstress = c; double c1c2=c1-c2; if (c1c2 > Tstress) Tstress = c1c2; if (fabs(Tstress-c) < 1.0e-15) Ttangent = E0; else Ttangent = Esh; // Determine if a load reversal has occurred due to the trial strain detectLoadReversal (dStrain); } } void Steel01::detectLoadReversal (double dStrain) { // Determine initial loading condition if (Tloading == 0 && dStrain != 0.0) { if (dStrain > 0.0) Tloading = 1; else Tloading = -1; } // Transition from loading to unloading, i.e. positive strain increment // to negative strain increment if (Tloading == 1 && dStrain < 0.0) { Tloading = -1; if (Cstrain > TmaxStrain) TmaxStrain = Cstrain; TshiftN = 1 + a1*pow((TmaxStrain-TminStrain)/(2.0*a2*epsy),0.8); } // Transition from unloading to loading, i.e. negative strain increment // to positive strain increment if (Tloading == -1 && dStrain > 0.0) { Tloading = 1; if (Cstrain < TminStrain) TminStrain = Cstrain; TshiftP = 1 + a3*pow((TmaxStrain-TminStrain)/(2.0*a4*epsy),0.8); } } double Steel01::getStrain () { return Tstrain; } double Steel01::getStress () { return Tstress; } double Steel01::getTangent () { return Ttangent; } double Steel01::getSecant () { if (fabs(Tstrain) > DBL_EPSILON) return Tstress/Tstrain; else return Ttangent; } int Steel01::commitState () { // History variables CminStrain = TminStrain; CmaxStrain = TmaxStrain; CshiftP = TshiftP; CshiftN = TshiftN; Cloading = Tloading; Cfailed = Tfailed; // State variables Cstrain = Tstrain; Cstress = Tstress; Ctangent = Ttangent; return 0; } int Steel01::revertToLastCommit () { // Reset trial history variables to last committed state setHistoryVariables(); // Reset trial state variables to last committed state Tstrain = Cstrain; Tstress = Cstress; Ttangent = Ctangent; return 0; } int Steel01::revertToStart () { // History variables CminStrain = 0.0; CmaxStrain = 0.0; CshiftP = 1.0; CshiftN = 1.0; Cloading = 0; Cfailed = 0; setHistoryVariables (); // State variables Cstrain = 0.0; Cstress = 0.0; Ctangent = E0; Tstrain = 0.0; Tstress = 0.0; Ttangent = E0; return 0; } UniaxialMaterial* Steel01::getCopy () { Steel01* theCopy = new Steel01(this->getTag(), fy, E0, b, a1, a2, a3, a4, epsmin, epsmax); // Calculated material properties theCopy->epsy = epsy; theCopy->Esh = Esh; // Converged history variables theCopy->CminStrain = CminStrain; theCopy->CmaxStrain = CmaxStrain; theCopy->CshiftP = CshiftP; theCopy->CshiftN = CshiftN; theCopy->Cloading = Cloading; theCopy->Cfailed = Cfailed; // Trial history variables theCopy->setHistoryVariables(); // Converged state variables theCopy->Cstrain = Cstrain; theCopy->Cstress = Cstress; theCopy->Ctangent = Ctangent; // Trial state variables theCopy->Tstrain = Tstrain; theCopy->Tstress = Tstress; theCopy->Ttangent = Ttangent; return theCopy; } int Steel01::sendSelf (int commitTag, Channel& theChannel) { int res = 0; static Vector data(19); data(0) = this->getTag(); // Material properties data(1) = fy; data(2) = E0; data(3) = b; data(4) = a1; data(5) = a2; data(6) = a3; data(7) = a4; data(8) = epsmin; data(9) = epsmax; // History variables from last converged state data(10) = CminStrain; data(11) = CmaxStrain; data(12) = CshiftP; data(13) = CshiftN; data(14) = Cloading; data(15) = Cfailed; // State variables from last converged state data(16) = Cstrain; data(17) = Cstress; data(18) = Ctangent; // Data is only sent after convergence, so no trial variables // need to be sent through data vector res = theChannel.sendVector(this->getDbTag(), commitTag, data); if (res < 0) cerr << "Steel01::sendSelf() - failed to send data\n"; return res; } int Steel01::recvSelf (int commitTag, Channel& theChannel, FEM_ObjectBroker& theBroker) { int res = 0; static Vector data(19); res = theChannel.recvVector(this->getDbTag(), commitTag, data); if (res < 0) { cerr << "Steel01::recvSelf() - failed to receive data\n"; this->setTag(0); } else { this->setTag(int(data(0))); // Material properties fy = data(1); E0 = data(2); b = data(3); a1 = data(4); a2 = data(5); a3 = data(6); a4 = data(7); epsmin = data(8); epsmax = data(9); epsy = fy/E0; Esh = b*E0; // History variables from last converged state CminStrain = data(10); CmaxStrain = data(11); CshiftP = data(12); CshiftN = data(13); Cloading = int(data(14)); Cfailed = int(data(15)); // Copy converged history values into trial values since data is only // sent (received) after convergence setHistoryVariables (); // State variables from last converged state Cstrain = data(16); Cstress = data(17); Ctangent = data(18); // Copy converged state values into trial values Tstrain = Cstrain; Tstress = Cstress; Ttangent = Ctangent; } return res; } void Steel01::Print (ostream& s, int flag) { s << "Steel01 tag: " << this->getTag() << endl; s << " fy: " << fy << endl; s << " E0: " << E0 << endl; s << " b: " << b << endl; s << " a1: " << a1 << endl; s << " a2: " << a2 << endl; s << " a3: " << a3 << endl; s << " a4: " << a4 << endl; if (epsmin != NEG_INF_STRAIN) s << " epsmin: " << epsmin << endl; if (epsmax != POS_INF_STRAIN) s << " epsmax: " << epsmax << endl; } int Steel01::setParameter(char **argv, int argc, Information &info) { if (argc < 1) return -1; if (strcmp(argv[0],"fy") == 0) { info.theType = DoubleType; return 1; } if (strcmp(argv[0],"E0") == 0) { info.theType = DoubleType; return 2; } if (strcmp(argv[0],"b") == 0) { info.theType = DoubleType; return 3; } if (strcmp(argv[0],"a1") == 0) { info.theType = DoubleType; return 4; } if (strcmp(argv[0],"a2") == 0) { info.theType = DoubleType; return 5; } if (strcmp(argv[0],"a3") == 0) { info.theType = DoubleType; return 6; } if (strcmp(argv[0],"a4") == 0) { info.theType = DoubleType; return 7; } if (strcmp(argv[0],"epsmin") == 0) { info.theType = DoubleType; return 8; } if (strcmp(argv[0],"epsmax") == 0) { info.theType = DoubleType; return 9; } else cerr << "WARNING: Could not set parameter in Steel01. " << endl; return -1; } int Steel01::updateParameter(int parameterID, Information &info) { switch (parameterID) { case -1: return -1; case 1: this->fy = info.theDouble; break; case 2: this->E0 = info.theDouble; break; case 3: this->b = info.theDouble; break; case 4: this->a1 = info.theDouble; break; case 5: this->a2 = info.theDouble; break; case 6: this->a3 = info.theDouble; break; case 7: this->a4 = info.theDouble; break; case 8: this->epsmin = info.theDouble; break; case 9: this->epsmax = info.theDouble; break; default: return -1; } epsy = fy/E0; // Yield strain Esh = b*E0; // Hardening modulus Ttangent = E0; // Initial stiffness return 0; }

Copyright

Contact Us