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Bond_SP01.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 $ // $Date: 2006/05/24 21:10:28 $ // Written: Jian Zhao, Iowa State University 04/2004 // Revision: Jian Zhao, University of Wisconsin, Milwaukee 04/2006 // // Description: This file contains the class defination for Uniaxial material Bond_SP01. // Bond_SP01: Strain penetration of rebars at footings w/o bond damage. #include <Bond_SP01.h> #include <Vector.h> #include <Matrix.h> #include <Channel.h> #include <Information.h> #include <math.h> #include <float.h> Bond_SP01::Bond_SP01 (int tag, double FY, double SY, double FU, double SU, double KZ, double r, double CD, double DB, double FC, double LA): UniaxialMaterial(tag,MAT_TAG_Bond_SP01), fy(FY), sy(SY), fu(FU), su(SU), Kz(KZ), R(r), Cd(CD), db(DB), fc(FC), lba(LA) { // Check units. Need parameters in ksi and in. if ( fy >= 1000 || sy >= 1) opserr << "WARNING: For the Strain-Penetration Model: input values in ksi and in." << endln; // Set bar stress-slip envelope Cr = 1.01; //% need to be large than 1 pretty arbitary Ks = pow(R,Kz/2.5); //% pretty arbitary // Assume symmetric envelope E0 = fy/sy; // bond condition (for future use) la = fy*db*1000.0/40.0/pow(fc*1000,0.5); // effective anchorage length // Set all history and state variables to initial values this->revertToStart (); } Bond_SP01::Bond_SP01 (int tag, double FY, double SY, double FU, double SU, double KZ, double r): UniaxialMaterial(tag,MAT_TAG_Bond_SP01), fy(FY), sy(SY), fu(FU), su(SU), Kz(KZ), R(r), Cd(0.0), db(1.0), fc(4.35), lba(0.0) { // Check units. Need parameters in ksi and in. if (fy >= 1000 || sy >= 1) opserr << "WARNING: WARNING: For the Strain-Penetration Model: input values in ksi and in." << endln; // Set bar stress-slip envelope (yield point) Cr = 1.01; //% need to be large than 1 pretty arbitary Ks = pow(R,Kz/2.5); //% pretty arbitary // Assume symmetric envelope E0 = fy/sy; // bond condition (for calculation) la = fy*db*1000.0/40.0/pow(fc*1000,0.5); // effective anchorage length // Set all history and state variables to initial values this->revertToStart (); } Bond_SP01::Bond_SP01 (): UniaxialMaterial(0,MAT_TAG_Bond_SP01), fy(64.0), sy(0.021), fu(102.2), su(1.0), Kz(0.3), R(.8), Cd(0.0), db(1.0), fc(4.35), lba(0.0) { // constructor w/o parameter. does nothing } Bond_SP01::~Bond_SP01 () { } int Bond_SP01::setTrialStrain (double strain, double strainRate) { // Reset history variables to last converged state TRSlip = CRSlip; // Return slip TRLoad = CRLoad; // Return load TRSlope = CRSlope; // Return slope TmaxHSlip = CmaxHSlip; // Maximum slip in tension TminHSlip = CminHSlip; // Maximum slip in compression Tloading = Cloading; // Loading flag TYieldFlag = CYieldFlag; // Yield flag // Set trial slip Tslip = strain; // Determine change in slip from last converged state double dslip = Tslip - Cslip; // Calculate the trial state given the trial Strain determineTrialState (Tslip, dslip); return 0; } int Bond_SP01::setTrial (double strain, double &stress, double &tangent, double strainRate) { // Reset history variables to last converged state TRSlip = CRSlip; // Return slip TRLoad = CRLoad; // Return load TRSlope = CRSlope; // Return slope TmaxHSlip = CmaxHSlip; // Maximum slip in tension TminHSlip = CminHSlip; // Maximum slip in compression Tloading = Cloading; // Loading flag TYieldFlag = CYieldFlag; // Yield flag // Set trial Strain Tslip = strain; // Determine change in Strain from last converged state double dslip; dslip = Tslip - Cslip; // Calculate the trial state given the trial Strain determineTrialState (Tslip, dslip); stress = Tload; tangent = Ttangent; return 0; } void Bond_SP01::determineTrialState (double ts, double dslip) { double maxrs; // maximum return slip in tension in history double maxrl; // maximum return load in tension in history double maxvgs; // maximum return vergin slip in tension in history double minrs; // maximum return slip in compression in history double minrl; // maximum return load in compression in history double minvgs; // maximum return vergin slip in compression in history double rslip; // last return slip double rload; // last return load double rsvg; // last return vergin slip double trs; // this return slip double trl; // this return load double trsvg; // this return vergin slip double Eun; // unloading slope (tension --> compression) double Ere; // reloading slope (compression --> tension) double Er; // return slope double kkk = 0.38; // unloading slope (damage) double templ, temps; // temporary virables double ss; // normalized slip double Sy; // dummy yield slip to keep reloadig slope E0 double ssy; // ratio of slip to Sy double suy; // ratio of dummy su to Sy double ft; // normalized load double st; // normalized slope if (fabs(dslip) <= DBL_EPSILON) //ignore trivial slip change { Tload = Cload; return; } if (Tloading == 0) { Tload = getEnvelopeStress(ts); if (dslip > 0.0) { Tloading = 1; CminHSlip = -ts; //avoid divided by zero } else { Tloading = -1; CmaxHSlip = -ts; //avoid divided by zero } return; } if (TYieldFlag == 0) { if (fabs(ts) <= sy) { Tload = ts*E0; Ttangent = E0; } else { TYieldFlag = 1; Tload = getEnvelopeStress(ts); } if (Tloading > 0 && dslip < 0.0 && Cslip > TmaxHSlip) TmaxHSlip = Cslip; if (Tloading < 0 && dslip > 0.0 && Cslip < TminHSlip) TminHSlip = Cslip; return; } //set limits maxrs = TmaxHSlip; maxrl = getEnvelopeStress(maxrs); if (maxrs > sy) { Eun = E0/pow(maxrs/sy,kkk); } else { Eun = E0; } maxvgs = maxrs-maxrl/Eun; minrs = TminHSlip; minrl = getEnvelopeStress(minrs); if (minrs < -sy) { Ere = E0/pow(-minrs/sy,kkk); } else { Ere = E0; } minvgs = minrs-minrl/Ere; rslip = TRSlip; rload = TRLoad; Er = TRSlope; rsvg = rslip-rload/Er; //get load for a slip if (Tloading > 0.0) //(Cloading>0): was loading (tension) { if (dslip > 0.0) //%(dslip>0): keep loading (tension) { if (ts >= maxrs) //%%envelope stress { Tload = getEnvelopeStress(ts); } else //%% ts < maxrs { if (ts >= rsvg) //%%curve reloading (tension) { Sy = maxrl/Ere; suy = (maxrs-rsvg)/Sy; if (ts-rsvg <= Ks*(maxrs-rsvg)) { ssy = (ts-rsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); Tload = ft*maxrl; st = pow(suy,(1-R))/pow(suy-ssy,2)/pow((pow(1/suy,R)+pow(ss,R)),(1/R+1)); Ttangent = st*Ere; } else { ssy = Ks*(maxrs-rsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); templ = ft*maxrl; temps = Ks*(maxrs-rsvg)+rsvg; Tload = templ+(maxrl-templ)/(maxrs-temps)*(ts-temps); Ttangent = (maxrl-templ)/(maxrs-temps); } } else //%% ts < rsvg { if (ts >= rslip) //%%linear reloading (tension) { Tload = rload*(ts-rsvg)/(rslip-rsvg); Ttangent = Er; } else //%%ts > rsvg not possible for safety { Tload = rload; } } } } else //%(dslip<0): turn unloading (compression) { Tloading = -1; TRSlip = Cslip; TRLoad = Cload; if (Cslip > TmaxHSlip) { TmaxHSlip = Cslip; if (TmaxHSlip > sy) { TRSlope = E0/pow(TmaxHSlip/sy, kkk); } else { TRSlope = E0; } } Er = TRSlope; trs = TRSlip; trl = TRLoad; trsvg = trs-trl/Er; if (trsvg > 0.0 && CminHSlip == 0.0) //%%guess a minimum return slip CminHSlip = -sy*trsvg/su; if (ts > trs) //%%not possible for safety { Tload = trl; } else { if (ts > trsvg) //%%linear unloading (compression) { Tload = trl*(ts-trsvg)/(trs-trsvg); Ttangent = Er; } else { if (ts > minrs) //%%curve unloading (compression) { Sy = minrl/Eun; suy = (minrs-trsvg)/Sy; if (ts-trsvg >= Ks*(minrs-trsvg)) { ssy = (ts-trsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); Tload = ft*minrl; st = pow(suy,(1-R))/pow(suy-ssy,2)/pow((pow(1/suy,R)+pow(ss,R)),(1/R+1)); Ttangent = st*Eun; } else { ssy = Ks*(minrs-trsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); templ = ft*minrl; temps = Ks*(minrs-trsvg)+trsvg; Tload = templ+(minrl-templ)/(minrs-temps)*(ts-temps); Ttangent = (minrl-templ)/(minrs-temps); } } else //%%envelope stress { Tload = getEnvelopeStress(ts); } } } } } else //(Tloading<0): was unloading (compression) { if (dslip < 0.0) //%(dslip<0): keep unloading (compression) { if (ts <= minrs) //%%envelope stress { Tload = getEnvelopeStress(ts); } else //%% ts > minrs { if (ts <= rsvg) //%%curve unloading (compression) { Sy = minrl/Eun; suy = (minrs-rsvg)/Sy; if (ts-rsvg >= Ks*(minrs-rsvg)) { ssy = (ts-rsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); Tload = ft*minrl; st = pow(suy,(1-R))/pow(suy-ssy,2)/pow((pow(1/suy,R)+pow(ss,R)),(1/R+1)); Ttangent = st*Eun; } else { ssy = Ks*(minrs-rsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); templ = ft*minrl; temps = Ks*(minrs-rsvg)+rsvg; Tload = templ+(minrl-templ)/(minrs-temps)*(ts-temps); Ttangent = (minrl-templ)/(minrs-temps); } } else //%% ts > rsvg { if (ts <= rslip) //%%linear unloading (compression) { Tload = rload*(ts-rsvg)/(rslip-rsvg); Ttangent = E0; } else //%%not possible for safety { Tload = rload; } } } } else //(dslip>0): turn loading (tension) { Tloading = 1; TRSlip = Cslip; TRLoad = Cload; if (Cslip < TminHSlip) { TminHSlip = Cslip; if (TminHSlip < -sy) { TRSlope = E0/pow(-TminHSlip/sy, kkk); } else { TRSlope = E0; } } Er = TRSlope; trs = TRSlip; trl = TRLoad; trsvg = trs-trl/Er; if (trsvg < 0.0 && CmaxHSlip == 0.0) CmaxHSlip = sy*trsvg/(-su); if (ts < trs) //%%not possible for safety { Tload = trl; } else //%% ts > trs { if (ts < trsvg) //%%linear unloading (compression) { Tload = trl*(ts-trsvg)/(trs-trsvg); Ttangent = Er; } else //%% ts > trsvg { if (ts < maxrs) //%%curve reloading (compression) { Sy = maxrl/Ere; suy = (maxrs-rsvg)/Sy; if (ts-trsvg <= Ks*(maxrs-trsvg)) { ssy = (ts-trsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); Tload = ft*maxrl; st = pow(suy,(1-R))/pow(suy-ssy,2)/pow((pow(1/suy,R)+pow(ss,R)),(1/R+1)); Ttangent = st*Ere; } else { ssy = Ks*(maxrs-trsvg)/Sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy,R)+pow(ss,R)),(1/R)); templ = ft*maxrl; temps = Ks*(maxrs-trsvg)+trsvg; Tload = templ+(maxrl-templ)/(maxrs-temps)*(ts-temps); Ttangent = (maxrl-templ)/(maxrs-temps); } } else //%%envelope stress { Tload = getEnvelopeStress(ts); } } } if (Cslip < TminHSlip) { TminHSlip = Cslip; } } } // Detect load reversals and determine damage indexes //this->detectloadReversal (dslip); } double Bond_SP01::getEnvelopeStress (double s) { double ss; // normalized slip double ft; // normalized load double st; // normalized slope double ssy; // the ratio of s-Sy to Sy double suy; // the ratio of su-Sy to Sy double load; if (fabs(s) < DBL_EPSILON) { load = 0.0; Ttangent = E0; return load; } if (s > 0.0) //tension side { if (s <= sy) { load = s*E0; //%stress Ttangent = E0; //%slope } else { if (s < su) { ssy = (s-sy)/sy; suy = (su-sy)/sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy/Kz,Cr)+pow(ss,Cr)),1/Cr); load = fy+ft*(fu-fy); st = (pow(suy,(1-Cr))/pow(Kz,Cr)/pow((suy-ssy),2))/pow((pow(1/suy/Kz,Cr)+pow(ss,Cr)),(1/Cr+1)); Ttangent = st*E0; } else { load = fu; Ttangent = 0.0; } } } else //compression side { if (s >= -sy) { load = s*E0; Ttangent = E0; } else { if (s > -su) { ssy = (s-(-sy))/(-sy); suy = (su-sy)/sy; ss = ssy/(suy-ssy); ft = ss/pow((pow(1/suy/Kz,Cr)+pow(ss,Cr)),1/Cr); load = -fy+ft*(-fu+fy); st = (pow(suy,(1-Cr))/pow(Kz,Cr)/pow((suy-ssy),2))/pow((pow(1/suy/Kz,Cr)+pow(ss,Cr)),(1/Cr+1)); Ttangent = st*E0; } else { load = -fu; Ttangent = 0.0; } } } return load; } double Bond_SP01::getStrain () { return Tslip; } double Bond_SP01::getStress () { return Tload; } double Bond_SP01::getTangent () { return Ttangent; } double Bond_SP01::getInitialTangent() { return fy/sy; } int Bond_SP01::commitState () { // History variables CRSlip = TRSlip; // Return slip CRLoad = TRLoad; // Return load CRSlope = TRSlope; // Return slope CmaxHSlip = TmaxHSlip; // Maximum slip in tension CminHSlip = TminHSlip; // Maximum slip in compression Cloading = Tloading; // Loading flag CYieldFlag = TYieldFlag; // Yield flag // State variables Cslip = Tslip; Cload = Tload; Ctangent = Ttangent; return 0; } int Bond_SP01::revertToLastCommit () { // Reset trial history variables to last committed state TRSlip = CRSlip; // Return slip TRLoad = CRLoad; // Return load TRSlope = CRSlope; // Return slope TmaxHSlip = CmaxHSlip; // Maximum slip in tension TminHSlip = CminHSlip; // Maximum slip in compression Tloading = Cloading; // Loading flag TYieldFlag = CYieldFlag; // Yield flag // Reset trial state variables to last committed state Tslip = Cslip; Tload = Cload; Ttangent = Ctangent; return 0; } int Bond_SP01::revertToStart () { // History variables CRSlip = 0.0; CRLoad = 0.0; CRSlope = E0; CmaxHSlip = 0.0; CminHSlip = 0.0; Cloading = 0; CYieldFlag = 0; TRSlip = 0.0; TRLoad = 0.0; TRSlope = E0; TmaxHSlip = 0.0; TminHSlip = 0.0; Tloading = 0; TYieldFlag = 0; // State variables Cslip = 0.0; Cload = 0.0; Ctangent = E0; Tslip = 0.0; Tload = 0.0; Ttangent = E0; return 0; } UniaxialMaterial* Bond_SP01::getCopy () { Bond_SP01* theCopy = new Bond_SP01(this->getTag(), fy, sy, fu, su, Kz, R, Cd, db, fc, lba); // Converged history variables theCopy->CRSlip = CRSlip; theCopy->CRLoad = CRLoad; theCopy->CRSlope = CRSlope; theCopy->CmaxHSlip = CmaxHSlip; theCopy->CminHSlip = CminHSlip; theCopy->Cloading = Cloading; theCopy->CYieldFlag = CYieldFlag; // Trial history variables theCopy->TRSlip = TRSlip; theCopy->TRLoad = TRLoad; theCopy->TRSlope = TRSlope; theCopy->TmaxHSlip = TmaxHSlip; theCopy->TminHSlip = TminHSlip; theCopy->Tloading = Tloading; theCopy->TYieldFlag = TYieldFlag; // Converged state variables theCopy->Cslip = Cslip; theCopy->Cload = Cload; theCopy->Ctangent = Ctangent; // Trial state variables theCopy->Tslip = Tslip; theCopy->Tload = Tload; theCopy->Ttangent = Ttangent; // Other global virables theCopy->Cr = Cr; theCopy->Ks = Ks; theCopy->E0 = E0; theCopy->la = la; return theCopy; } int Bond_SP01::sendSelf (int commitTag, Channel& theChannel) { return -1; } int Bond_SP01::recvSelf (int commitTag, Channel& theChannel, FEM_ObjectBroker& theBroker) { return -1; } void Bond_SP01::Print (OPS_Stream& s, int flag) { s << "Bond_SP01 tag: " << this->getTag() << endln; s << " sy: " << sy << " "; s << " fy: " << fy << " "; s << " su: " << su << " "; s << " fu: " << fu << " "; s << " Kz: " << Kz << " "; s << " R: " << R << " "; s << " Cd: " << Cd << " "; s << " db: " << db << " "; s << " fc: " << fc << " "; s << " lba:" << lba << " "; } Generated on Mon Oct 23 15:05:19 2006 for OpenSees by  1.5.0

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