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Steel02.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: 1.2 $ // $Date: 2006/03/23 23:02:00 $ // $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/Steel02.cpp,v $ // Written: fmk // Created: 03/06 // // Description: This file contains the class implementation of Steel02. // This Steel02 is based on an f2c of the FEDEAS material // Steel02.f which is: //----------------------------------------------------------------------- // MENEGOTTO-PINTO STEEL MODEL WITH FILIPPOU ISOTROPIC HARDENING // written by MOHD YASSIN (1993) // adapted to FEDEAS material library // by E. Spacone, G. Monti and F.C. Filippou (1994) //----------------------------------------------------------------------- #include <stdlib.h> #include <Steel02.h> #include <OPS_Globals.h> #include <float.h> #include <Channel.h> Steel02::Steel02(int tag, double _Fy, double _E0, double _b, double _R0, double _cR1, double _cR2, double _a1, double _a2, double _a3, double _a4): UniaxialMaterial(tag, MAT_TAG_Steel02), Fy(_Fy), E0(_E0), b(_b), R0(_R0), cR1(_cR1), cR2(_cR2), a1(_a1), a2(_a2), a3(_a3), a4(_a4) { konP = 0; kon = 0; eP = E0; epsP = 0.0; sigP = 0.0; sig = 0.0; eps = 0.0; e = E0; epsmaxP = Fy/E0; epsminP = -epsmaxP; epsplP = 0.0; epss0P = 0.0; sigs0P = 0.0; epssrP = 0.0; sigsrP = 0.0; } Steel02::Steel02(int tag, double _Fy, double _E0, double _b, double _R0, double _cR1, double _cR2): UniaxialMaterial(tag, MAT_TAG_Steel02), Fy(_Fy), E0(_E0), b(_b), R0(_R0), cR1(_cR1), cR2(_cR2) { konP = 0; // Default values for no isotropic hardening a1 = 0.0; a2 = 1.0; a3 = 0.0; a4 = 1.0; eP = E0; epsP = 0.0; sigP = 0.0; sig = 0.0; eps = 0.0; e = E0; epsmaxP = Fy/E0; epsminP = -epsmaxP; epsplP = 0.0; epss0P = 0.0; sigs0P = 0.0; epssrP = 0.0; sigsrP = 0.0; } Steel02::Steel02(int tag, double _Fy, double _E0, double _b): UniaxialMaterial(tag, MAT_TAG_Steel02), Fy(_Fy), E0(_E0), b(_b) { konP = 0; // Default values for elastic to hardening transitions R0 = 15.0; cR1 = 0.925; cR2 = 0.15; // Default values for no isotropic hardening a1 = 0.0; a2 = 1.0; a3 = 0.0; a4 = 1.0; eP = E0; epsP = 0.0; sigP = 0.0; sig = 0.0; eps = 0.0; e = E0; epsmaxP = Fy/E0; epsminP = -epsmaxP; epsplP = 0.0; epss0P = 0.0; sigs0P = 0.0; epssrP = 0.0; sigsrP = 0.0; } Steel02::Steel02(void): UniaxialMaterial(0, MAT_TAG_Steel02) { konP = 0; } Steel02::~Steel02(void) { // Does nothing } UniaxialMaterial* Steel02::getCopy(void) { Steel02 *theCopy = new Steel02(this->getTag(), Fy, E0, b, R0, cR1, cR2, a1, a2, a3, a4); return theCopy; } double Steel02::getInitialTangent(void) { return E0; } int Steel02::setTrialStrain(double trialStrain, double strainRate) { double Esh = b * E0; double epsy = Fy / E0; eps = trialStrain; double deps = eps - epsP; epsmax = epsmaxP; epsmin = epsminP; epspl = epsplP; epss0 = epss0P; sigs0 = sigs0P; epsr = epssrP; sigr = sigsrP; kon = konP; if (kon == 0) { if (fabs(deps) < 10.0*DBL_EPSILON) { e = E0; sig = 0.; return 0; } else { epsmax = epsy; epsmin = -epsy; if (deps < 0.0) { kon = 2; epss0 = epsmin; sigs0 = -Fy; epspl = epsmin; } else { kon = 1; epss0 = epsmax; sigs0 = Fy; epspl = epsmax; } } } // in case of load reversal from negative to positive strain increment, // update the minimum previous strain, store the last load reversal // point and calculate the stress and strain (sigs0 and epss0) at the // new intersection between elastic and strain hardening asymptote // To include isotropic strain hardening shift the strain hardening // asymptote by sigsft before calculating the intersection point // Constants a3 and a4 control this stress shift on the tension side if (kon == 2 && deps > 0.0) { kon = 1; epsr = epsP; sigr = sigP; //epsmin = min(epsP, epsmin); if (epsP < epsmin) epsmin = epsP; double d1 = (epsmax - epsmin) / (2.0*(a4 * epsy)); double shft = 1.0 + a3 * pow(d1, 0.8); epss0 = (Fy * shft - Esh * epsy * shft - sigr + E0 * epsr) / (E0 - Esh); sigs0 = Fy * shft + Esh * (epss0 - epsy * shft); epspl = epsmax; } else { // in case of load reversal from positive to negative strain increment // update the maximum previous strain, store the last load reversal // point and calculate the stress and strain (sigs0 and epss0) at the // new intersection between elastic and strain hardening asymptote // To include isotropic strain hardening shift the strain hardening // asymptote by sigsft before calculating the intersection point // Constants a1 and a2 control this stress shift on compression side if (kon == 1 && deps < 0.0) { kon = 2; epsr = epsP; sigr = sigP; // epsmax = max(epsP, epsmax); if (epsP > epsmax) epsmax = epsP; double d1 = (epsmax - epsmin) / (2.0*(a2 * epsy)); double shft = 1.0 + a1 * pow(d1, 0.8); epss0 = (-Fy * shft + Esh * epsy * shft - sigr + E0 * epsr) / (E0 - Esh); sigs0 = -Fy * shft + Esh * (epss0 + epsy * shft); epspl = epsmin; } } // calculate current stress sig and tangent modulus E double xi = fabs((epspl-epss0)/epsy); double R = R0*(1.0 - (cR1*xi)/(cR2+xi)); double epsrat = (eps-epsr)/(epss0-epsr); double dum1 = 1.0 + pow(fabs(epsrat),R); double dum2 = pow(dum1,(1/R)); sig = b*epsrat +(1.0-b)*epsrat/dum2; sig = sig*(sigs0-sigr)+sigr; e = b + (1.0-b)/(dum1*dum2); e = e*(sigs0-sigr)/(epss0-epsr); return 0; } double Steel02::getStrain(void) { return eps; } double Steel02::getStress(void) { return sig; } double Steel02::getTangent(void) { return e; } int Steel02::commitState(void) { epsminP = epsmin; epsmaxP = epsmax; epsplP = epspl; epss0P = epss0; sigs0P = sigs0; epssrP = epsr; sigsrP = sigr; konP = kon; eP = e; sigP = sig; epsP = eps; return 0; } int Steel02::revertToLastCommit(void) { epsmin = epsminP; epsmax = epsmaxP; epspl = epsplP; epss0 = epss0P; sigs0 = sigs0P; epsr = epssrP; sigr = sigsrP; kon = konP; e = eP; sig = sigP; eps = epsP; return 0; } int Steel02::revertToStart(void) { eP = E0; epsP = 0.0; sigP = 0.0; sig = 0.0; eps = 0.0; e = E0; konP = 0; epsmaxP = Fy/E0; epsminP = -epsmaxP; epsplP = 0.0; epss0P = 0.0; sigs0P = 0.0; epssrP = 0.0; sigsrP = 0.0; return 0; } int Steel02::sendSelf(int commitTag, Channel &theChannel) { static Vector data(22); data(0) = Fy; data(1) = E0; data(2) = b; data(3) = R0; data(4) = cR1; data(5) = cR2; data(6) = a1; data(7) = a2; data(8) = a3; data(9) = a4; data(10) = epsminP; data(11) = epsmaxP; data(12) = epsplP; data(13) = epss0P; data(14) = sigs0P; data(15) = epssrP; data(16) = sigsrP; data(17) = konP; data(18) = epsP; data(19) = sigP; data(20) = eP; data(21) = this->getTag(); if (theChannel.sendVector(this->getDbTag(), commitTag, data) < 0) { opserr << "Steel02::sendSelf() - failed to sendSelf\n"; return -1; } return 0; } int Steel02::recvSelf(int commitTag, Channel &theChannel, FEM_ObjectBroker &theBroker) { static Vector data(22); if (theChannel.sendVector(this->getDbTag(), commitTag, data) < 0) { opserr << "Steel02::recvSelf() - failed to recvSelf\n"; return -1; } Fy = data(0); E0 = data(1); b = data(2); R0 = data(3); cR1 = data(4); cR2 = data(5); a1 = data(6); a2 = data(7); a3 = data(8); a4 = data(9); epsminP = data(10); epsmaxP = data(11); epsplP = data(12); epss0P = data(13); sigs0P = data(14); epssrP = data(15); sigsrP = data(16); konP = data(17); epsP = data(18); sigP = data(19); eP = data(20); this->setTag(data(21)); e = eP; sig = sigP; eps = epsP; return 0; } void Steel02::Print(OPS_Stream &s, int flag) { s << "Steel02:(strain, stress, tangent) " << eps << " " << sig << " " << e << endln; } Generated on Mon Oct 23 15:05:22 2006 for OpenSees by  1.5.0

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