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HardeningMaterial.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: 1.1.1.1 $ // $Date: 2000/09/15 08:23:22 $ // $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/HardeningMaterial.cpp,v $ // File: ~/material/HardeningMaterial.C // // Written: MHS // Created: May 2000 // Revision: A // // Description: This file contains the class implementation for // HardeningMaterial. // // What: "@(#) HardeningMaterial.C, revA" #include <HardeningMaterial.h> #include <Vector.h> #include <Channel.h> #include <math.h> HardeningMaterial::HardeningMaterial(int tag, double e, double s, double k, double h) :UniaxialMaterial(tag,MAT_TAG_Hardening), E(e), sigmaY(s), K(k), H(h) { this->revertToStart(); this->revertToLastCommit(); } HardeningMaterial::HardeningMaterial() :UniaxialMaterial(0,MAT_TAG_Hardening), E(0.0), sigmaY(0.0), K(0.0), H(0.0) { this->revertToStart(); this->revertToLastCommit(); } HardeningMaterial::~HardeningMaterial() { // does nothing } int HardeningMaterial::setTrialStrain (double strain, double strainRate) { // Set total strain Tstrain = strain; // Elastic trial stress Tstress = E * (Tstrain-CplasticStrain); // Compute trial stress relative to committed back stress double xsi = Tstress - CbackStress; // Compute yield criterion double f = fabs(xsi) - (sigmaY + K*Chardening); // Elastic step ... no updates required if (f <= 0.0) { // Set trial tangent Ttangent = E; } // Plastic step ... perform return mapping algorithm else { // Compute consistency parameter double dGamma = f / (E+K+H); // Find sign of xsi int sign = (xsi < 0) ? -1 : 1; // Bring trial stress back to yield surface Tstress -= dGamma*E*sign; // Update plastic strain TplasticStrain = CplasticStrain + dGamma*sign; // Update back stress TbackStress = CbackStress + dGamma*H*sign; // Update internal hardening variable Thardening = Chardening + dGamma; // Set trial tangent Ttangent = E*(H+K) / (E+H+K); } return 0; } double HardeningMaterial::getStress(void) { return Tstress; } double HardeningMaterial::getTangent(void) { return Ttangent; } double HardeningMaterial::getSecant (void) { if (Tstrain != 0.0) return Tstress/Tstrain; else return E; } double HardeningMaterial::getStrain(void) { return Tstrain; } int HardeningMaterial::commitState(void) { // Commit trial state variables Cstrain = Tstrain; CplasticStrain = TplasticStrain; CbackStress = TbackStress; Chardening = Thardening; // Do not need to commit the trial stress or trial tangent return 0; } int HardeningMaterial::revertToLastCommit(void) { // Set trial state to last committed state Tstrain = Cstrain; TplasticStrain = CplasticStrain; TbackStress = CbackStress; Thardening = Chardening; // Recompute trial stress and trial tangent this->setTrialStrain(Cstrain); return 0; } int HardeningMaterial::revertToStart(void) { // Reset committed state variables Cstrain = 0.0; CplasticStrain = 0.0; CbackStress = 0.0; Chardening = 0.0; // Reset the trial state this->revertToLastCommit(); return 0; } UniaxialMaterial * HardeningMaterial::getCopy(void) { HardeningMaterial *theCopy = new HardeningMaterial(this->getTag(), E, sigmaY, K, H); // Copy trial state variables theCopy->Tstrain = Tstrain; theCopy->Tstress = Tstress; theCopy->Ttangent = Ttangent; theCopy->TplasticStrain = TplasticStrain; theCopy->TbackStress = TbackStress; theCopy->Thardening = Thardening; // Copy committed state variables theCopy->Cstrain = Cstrain; theCopy->CplasticStrain = CplasticStrain; theCopy->CbackStress = CbackStress; theCopy->Chardening = Chardening; return theCopy; } int HardeningMaterial::sendSelf(int cTag, Channel &theChannel) { int res = 0; static Vector data(9); data(0) = this->getTag(); data(1) = E; data(2) = sigmaY; data(3) = K; data(4) = H; data(5) = Cstrain; data(6) = CplasticStrain; data(7) = CbackStress; data(8) = Chardening; res = theChannel.sendVector(this->getDbTag(), cTag, data); if (res < 0) cerr << "HardeningMaterial::sendSelf() - failed to send data\n"; return res; } int HardeningMaterial::recvSelf(int cTag, Channel &theChannel, FEM_ObjectBroker &theBroker) { int res = 0; static Vector data(9); res = theChannel.recvVector(this->getDbTag(), cTag, data); if (res < 0) { cerr << "HardeningMaterial::recvSelf() - failed to receive data\n"; E = 0; this->setTag(0); } else { this->setTag((int)data(0)); E = data(1); sigmaY = data(2); K = data(3); H = data(4); Cstrain = data(5); CplasticStrain = data(6); CbackStress = data(7); Chardening = data(8); // Set the trial state variables revertToLastCommit(); } return res; } void HardeningMaterial::Print(ostream &s, int flag) { s << "HardeningMaterial, tag: " << this->getTag() << endl; s << " E: " << E << endl; s << " sigmaY: " << sigmaY << endl; s << " K: " << K << endl; s << " H: " << H << endl; }

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