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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: 1.12 $ // $Date: 2006/09/05 22:22:58 $ // $Source: /usr/local/cvs/OpenSees/SRC/material/uniaxial/HardeningMaterial.cpp,v $ // Written: MHS // Created: May 2000 // Revision: A // // Description: This file contains the class implementation for // HardeningMaterial. #include <HardeningMaterial.h> #include <Vector.h> #include <Channel.h> #include <Matrix.h> #include <Information.h> #include <Parameter.h> #include <math.h> #include <float.h> HardeningMaterial::HardeningMaterial(int tag, double e, double s, double hi, double hk, double n) :UniaxialMaterial(tag,MAT_TAG_Hardening), E(e), sigmaY(s), Hiso(hi), Hkin(hk), eta(n) { // AddingSensitivity:BEGIN ///////////////////////////////////// parameterID = 0; SHVs = 0; // AddingSensitivity:END ////////////////////////////////////// // Initialize variables this->revertToStart(); } HardeningMaterial::HardeningMaterial() :UniaxialMaterial(0,MAT_TAG_Hardening), E(0.0), sigmaY(0.0), Hiso(0.0), Hkin(0.0), eta(0.0) { // AddingSensitivity:BEGIN ///////////////////////////////////// parameterID = 0; SHVs = 0; // AddingSensitivity:END ////////////////////////////////////// // Initialize variables this->revertToStart(); } HardeningMaterial::~HardeningMaterial() { // AddingSensitivity:BEGIN ///////////////////////////////////// if (SHVs != 0) delete SHVs; // AddingSensitivity:END ////////////////////////////////////// } int HardeningMaterial::setTrialStrain (double strain, double strainRate) { if (fabs(Tstrain-strain) < DBL_EPSILON) return 0; // 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 + Hiso*Chardening); // Elastic step ... no updates required if (f <= -DBL_EPSILON * E) { //if (f <= 1.0e-8) { // Set trial tangent Ttangent = E; } // Plastic step ... perform return mapping algorithm else { double etadt = 0.0; if (eta != 0.0 || ops_Dt != 0) etadt = eta/ops_Dt; // Compute consistency parameter double dGamma = f / (E+Hiso+Hkin+etadt); // 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*Hkin*sign; // Update internal hardening variable Thardening = Chardening + dGamma; // Set trial tangent Ttangent = E*(Hkin+Hiso+etadt) / (E+Hkin+Hiso+etadt); } return 0; } double HardeningMaterial::getStress(void) { return Tstress; } double HardeningMaterial::getTangent(void) { return Ttangent; } double HardeningMaterial::getStrain(void) { return Tstrain; } int HardeningMaterial::commitState(void) { // Commit trial history variables CplasticStrain = TplasticStrain; CbackStress = TbackStress; Chardening = Thardening; return 0; } int HardeningMaterial::revertToLastCommit(void) { return 0; } int HardeningMaterial::revertToStart(void) { // Reset committed history variables CplasticStrain = 0.0; CbackStress = 0.0; Chardening = 0.0; // Reset trial history variables TplasticStrain = 0.0; TbackStress = 0.0; Thardening = 0.0; // Initialize state variables Tstrain = 0.0; Tstress = 0.0; Ttangent = E; // AddingSensitivity:BEGIN ///////////////////////////////// if (SHVs != 0) SHVs->Zero(); // AddingSensitivity:END ////////////////////////////////// return 0; } UniaxialMaterial * HardeningMaterial::getCopy(void) { HardeningMaterial *theCopy = new HardeningMaterial(this->getTag(), E, sigmaY, Hiso, Hkin, eta); // Copy committed history variables theCopy->CplasticStrain = CplasticStrain; theCopy->CbackStress = CbackStress; theCopy->Chardening = Chardening; // Copy trial history variables theCopy->TplasticStrain = TplasticStrain; theCopy->TbackStress = TbackStress; theCopy->Thardening = Thardening; // Copy trial state variables theCopy->Tstrain = Tstrain; theCopy->Tstress = Tstress; theCopy->Ttangent = Ttangent; return theCopy; } int HardeningMaterial::sendSelf(int cTag, Channel &theChannel) { int res = 0; static Vector data(12); data(0) = this->getTag(); data(1) = E; data(2) = sigmaY; data(3) = Hiso; data(4) = Hkin; data(5) = eta; data(6) = CplasticStrain; data(7) = CbackStress; data(8) = Chardening; data(9) = Tstrain; data(10) = Tstress; data(11) = Ttangent; res = theChannel.sendVector(this->getDbTag(), cTag, data); if (res < 0) opserr << "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(12); res = theChannel.recvVector(this->getDbTag(), cTag, data); if (res < 0) { opserr << "HardeningMaterial::recvSelf() - failed to receive data\n"; E = 0; this->setTag(0); } else { this->setTag((int)data(0)); E = data(1); sigmaY = data(2); Hiso = data(3); Hkin = data(4); eta = data(5); CplasticStrain = data(6); CbackStress = data(7); Chardening = data(8); Tstrain = data(9); Tstress = data(10); Ttangent = data(11); } return res; } void HardeningMaterial::Print(OPS_Stream &s, int flag) { s << "HardeningMaterial, tag: " << this->getTag() << endln; s << " E: " << E << endln; s << " sigmaY: " << sigmaY << endln; s << " Hiso: " << Hiso << endln; s << " Hkin: " << Hkin << endln; s << " eta: " << eta << endln; } // AddingSensitivity:BEGIN /////////////////////////////////// int HardeningMaterial::setParameter(const char **argv, int argc, Parameter &param) { if (argc < 1) return -1; if (strcmp(argv[0],"sigmaY") == 0 || strcmp(argv[0],"fy") == 0) return param.addObject(1, this); if (strcmp(argv[0],"E") == 0) return param.addObject(2, this); if (strcmp(argv[0],"H_kin") == 0) return param.addObject(3, this); if (strcmp(argv[0],"H_iso") == 0) return param.addObject(4, this); else opserr << "WARNING: Could not set parameter in HardeningMaterial. " << endln; return -1; } int HardeningMaterial::updateParameter(int parameterID, Information &info) { switch (parameterID) { case -1: return -1; case 1: this->sigmaY = info.theDouble; break; case 2: this->E = info.theDouble; break; case 3: this->Hkin = info.theDouble; break; case 4: this->Hiso = info.theDouble; break; default: return -1; } return 0; } int HardeningMaterial::activateParameter(int passedParameterID) { parameterID = passedParameterID; return 0; } double HardeningMaterial::getStressSensitivity(int gradNumber, bool conditional) { // First set values depending on what is random double SigmaYSensitivity = 0.0; double ESensitivity = 0.0; double HkinSensitivity = 0.0; double HisoSensitivity = 0.0; if (parameterID == 1) { // sigmaY SigmaYSensitivity = 1.0; } else if (parameterID == 2) { // E ESensitivity = 1.0; } else if (parameterID == 3) { // Hkin HkinSensitivity = 1.0; } else if (parameterID == 4) { // Hiso HisoSensitivity = 1.0; } else { // Nothing random here, but may have to return something in any case } // Then pick up history variables for this gradient number double CplasticStrainSensitivity = 0.0; double CbackStressSensitivity = 0.0; double ChardeningSensitivity = 0.0; if (SHVs != 0) { CplasticStrainSensitivity = (*SHVs)(0,(gradNumber-1)); CbackStressSensitivity = (*SHVs)(1,(gradNumber-1)); ChardeningSensitivity = (*SHVs)(2,(gradNumber-1)); } // Elastic trial stress double Tstress = E * (Tstrain-CplasticStrain); // Compute trial stress relative to committed back stress double xsi = Tstress - CbackStress; // Compute yield criterion double f = fabs(xsi) - (sigmaY + Hiso*Chardening); double sensitivity; // Elastic step ... no updates required if (f <= -DBL_EPSILON * E) { //if (f <= 1.0e-8) { sensitivity = ESensitivity*(Tstrain-CplasticStrain)-E*CplasticStrainSensitivity; } // Plastic step else { double TstressSensitivity = ESensitivity*(Tstrain-CplasticStrain)-E*CplasticStrainSensitivity; int sign = (xsi < 0) ? -1 : 1; double dGamma = f / (E+Hiso+Hkin); double fSensitivity = (TstressSensitivity-CbackStressSensitivity)*sign - SigmaYSensitivity - HisoSensitivity*Chardening - Hiso*ChardeningSensitivity; double dGammaSensitivity = (fSensitivity*(E+Hkin+Hiso)-f*(ESensitivity+HkinSensitivity+HisoSensitivity)) /((E+Hkin+Hiso)*(E+Hkin+Hiso)); sensitivity = (TstressSensitivity-dGammaSensitivity*E*sign-dGamma*ESensitivity*sign); } return sensitivity; } double HardeningMaterial::getInitialTangentSensitivity(int gradNumber) { // For now, assume that this is only called for initial stiffness if (parameterID == 2) { return 1.0; } else { return 0.0; } } int HardeningMaterial::commitSensitivity(double TstrainSensitivity, int gradNumber, int numGrads) { if (SHVs == 0) { SHVs = new Matrix(3,numGrads); } // First set values depending on what is random double SigmaYSensitivity = 0.0; double ESensitivity = 0.0; double HkinSensitivity = 0.0; double HisoSensitivity = 0.0; if (parameterID == 1) { // sigmaY SigmaYSensitivity = 1.0; } else if (parameterID == 2) { // E ESensitivity = 1.0; } else if (parameterID == 3) { // Hkin HkinSensitivity = 1.0; } else if (parameterID == 4) { // Hiso HisoSensitivity = 1.0; } else { // Nothing random here, but may have to save SHV's in any case } // Then pick up history variables for this gradient number double CplasticStrainSensitivity= (*SHVs)(0,(gradNumber-1)); double CbackStressSensitivity = (*SHVs)(1,(gradNumber-1)); double ChardeningSensitivity = (*SHVs)(2,(gradNumber-1)); // Elastic trial stress double Tstress = E * (Tstrain-CplasticStrain); // Compute trial stress relative to committed back stress double xsi = Tstress - CbackStress; // Compute yield criterion double f = fabs(xsi) - (sigmaY + Hiso*Chardening); // Elastic step ... no updates required if (f <= -DBL_EPSILON * E) { //if (f <= 1.0e-8) { // No changes in the sensitivity history variables } // Plastic step else { double TstressSensitivity = ESensitivity*(Tstrain-CplasticStrain) + E*(TstrainSensitivity-CplasticStrainSensitivity); int sign = (xsi < 0) ? -1 : 1; double dGamma = f / (E+Hiso+Hkin); double fSensitivity = (TstressSensitivity-CbackStressSensitivity)*sign - SigmaYSensitivity - HisoSensitivity*Chardening - Hiso*ChardeningSensitivity; double dGammaSensitivity = (fSensitivity*(E+Hkin+Hiso)-f*(ESensitivity+HkinSensitivity+HisoSensitivity)) /((E+Hkin+Hiso)*(E+Hkin+Hiso)); (*SHVs)(0,(gradNumber-1)) += dGammaSensitivity*sign; (*SHVs)(1,(gradNumber-1)) += dGammaSensitivity*Hkin*sign + dGamma*HkinSensitivity*sign; (*SHVs)(2,(gradNumber-1)) += dGammaSensitivity; } return 0; } // AddingSensitivity:END ///////////////////////////////////////////// Generated on Mon Oct 23 15:05:20 2006 for OpenSees by  1.5.0

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