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CorotTruss.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: 2001/07/20 19:27:00 $ // $Source: /usr/local/cvs/OpenSees/SRC/element/truss/CorotTruss.cpp,v $ // Written: MHS // Created: May 2001 // // Description: This file contains the class implementation for CorotTruss. #include <CorotTruss.h> #include <Information.h> #include <Domain.h> #include <Node.h> #include <Channel.h> #include <FEM_ObjectBroker.h> #include <UniaxialMaterial.h> #include <Renderer.h> #include <G3Globals.h> #include <math.h> #include <stdlib.h> #include <string.h> #include <ElementResponse.h> Matrix CorotTruss::M2(2,2); Matrix CorotTruss::M4(4,4); Matrix CorotTruss::M6(6,6); Matrix CorotTruss::M12(12,12); Vector CorotTruss::V2(2); Vector CorotTruss::V4(4); Vector CorotTruss::V6(6); Vector CorotTruss::V12(12); // constructor: // responsible for allocating the necessary space needed by each object // and storing the tags of the CorotTruss end nodes. CorotTruss::CorotTruss(int tag, int dim, int Nd1, int Nd2, UniaxialMaterial &theMat, double a, double rho) :Element(tag,ELE_TAG_CorotTruss), theMaterial(0), connectedExternalNodes(2), numDOF(0), numDIM(dim), Lo(0.0), Ln(0.0), R(3,3), A(a), M(rho), end1Ptr(0), end2Ptr(0), theMatrix(0), theVector(0) { // get a copy of the material and check we obtained a valid copy theMaterial = theMat.getCopy(); if (theMaterial == 0) g3ErrorHandler->fatal("FATAL CorotTruss::CorotTruss - %d %s %d\n", tag, "failed to get a copy of material with tag ", theMat.getTag()); // ensure the connectedExternalNode ID is of correct size & set values if (connectedExternalNodes.Size() != 2) g3ErrorHandler->fatal("FATAL CorotTruss::CorotTruss - %d %s\n", tag, "failed to create an ID of size 2"); connectedExternalNodes(0) = Nd1; connectedExternalNodes(1) = Nd2; } // constructor: // invoked by a FEM_ObjectBroker - blank object that recvSelf needs // to be invoked upon CorotTruss::CorotTruss() :Element(0,ELE_TAG_CorotTruss), theMaterial(0),connectedExternalNodes(2), numDOF(0), numDIM(0), Lo(0.0), Ln(0.0), R(3,3), A(0.0), M(0.0), end1Ptr(0), end2Ptr(0), theMatrix(0), theVector(0) { // ensure the connectedExternalNode ID is of correct size if (connectedExternalNodes.Size() != 2) g3ErrorHandler->fatal("FATAL CorotTruss::CorotTruss - %s\n", "failed to create an ID of size 2"); } // destructor // delete must be invoked on any objects created by the object // and on the matertial object. CorotTruss::~CorotTruss() { // invoke the destructor on any objects created by the object // that the object still holds a pointer to if (theMaterial != 0) delete theMaterial; } int CorotTruss::getNumExternalNodes(void) const { return 2; } const ID & CorotTruss::getExternalNodes(void) { return connectedExternalNodes; } int CorotTruss::getNumDOF(void) { return numDOF; } // method: setDomain() // to set a link to the enclosing Domain and to set the node pointers. // also determines the number of dof associated // with the CorotTruss element, we set matrix and vector pointers, // allocate space for t matrix, determine the length // and set the transformation matrix. void CorotTruss::setDomain(Domain *theDomain) { // check Domain is not null - invoked when object removed from a domain if (theDomain == 0) { end1Ptr = 0; end2Ptr = 0; Lo = 0.0; Ln = 0.0; return; } // first set the node pointers int Nd1 = connectedExternalNodes(0); int Nd2 = connectedExternalNodes(1); end1Ptr = theDomain->getNode(Nd1); end2Ptr = theDomain->getNode(Nd2); // if can't find both - send a warning message if ((end1Ptr == 0) || (end2Ptr == 0)) { g3ErrorHandler->warning("CorotTruss::setDomain() - CorotTruss %d node %d %s\n", this->getTag(), Nd1, "does not exist in the model"); // fill this in so don't segment fault later numDOF = 6; return; } // now determine the number of dof and the dimesnion int dofNd1 = end1Ptr->getNumberDOF(); int dofNd2 = end2Ptr->getNumberDOF(); // if differing dof at the ends - print a warning message if (dofNd1 != dofNd2) { g3ErrorHandler->warning("WARNING CorotTruss::setDomain(): nodes %d and %d %s %d\n",Nd1, Nd2, "have differing dof at ends for CorotTruss",this->getTag()); // fill this in so don't segment fault later numDOF = 6; return; } if (numDIM == 1 && dofNd1 == 1) { numDOF = 2; theMatrix = &M2; theVector = &V2; } else if (numDIM == 2 && dofNd1 == 2) { numDOF = 4; theMatrix = &M4; theVector = &V4; } else if (numDIM == 2 && dofNd1 == 3) { numDOF = 6; theMatrix = &M6; theVector = &V6; } else if (numDIM == 3 && dofNd1 == 3) { numDOF = 6; theMatrix = &M6; theVector = &V6; } else if (numDIM == 3 && dofNd1 == 6) { numDOF = 12; theMatrix = &M12; theVector = &V12; } else { g3ErrorHandler->warning("%s -- nodal DOF %d not compatible with element", "CorotTruss::setDomain", dofNd1); // fill this in so don't segment fault later numDOF = 6; return; } // call the base class method this->DomainComponent::setDomain(theDomain); // now determine the length, cosines and fill in the transformation // NOTE t = -t(every one else uses for residual calc) const Vector &end1Crd = end1Ptr->getCrds(); const Vector &end2Crd = end2Ptr->getCrds(); // Determine global offsets double cosX[3]; cosX[0] = 0.0; cosX[1] = 0.0; cosX[2] = 0.0; int i; for (i = 0; i < numDIM; i++) { cosX[i] += end2Crd(i)-end1Crd(i); } // Set undeformed and initial length Lo = cosX[0]*cosX[0] + cosX[1]*cosX[1] + cosX[2]*cosX[2]; Lo = sqrt(Lo); Ln = Lo; // Initial offsets d21[0] = Lo; d21[1] = 0.0; d21[2] = 0.0; // Set global orientation cosX[0] /= Lo; cosX[1] /= Lo; cosX[2] /= Lo; R(0,0) = cosX[0]; R(0,1) = cosX[1]; R(0,2) = cosX[2]; // Element lies outside the YZ plane if (fabs(cosX[0]) > 0.0) { R(1,0) = -cosX[1]; R(1,1) = cosX[0]; R(1,2) = 0.0; R(2,0) = -cosX[0]*cosX[2]; R(2,1) = -cosX[1]*cosX[2]; R(2,2) = cosX[0]*cosX[0] + cosX[1]*cosX[1]; } // Element is in the YZ plane else { R(1,0) = 0.0; R(1,1) = -cosX[2]; R(1,2) = cosX[1]; R(2,0) = 1.0; R(2,1) = 0.0; R(2,2) = 0.0; } // Orthonormalize last two rows of R double norm; for (i = 1; i < 3; i++) { norm = sqrt(R(i,0)*R(i,0) + R(i,1)*R(i,1) + R(i,2)*R(i,2)); R(i,0) /= norm; R(i,1) /= norm; R(i,2) /= norm; } // Set lumped mass M = M*Lo/2; } int CorotTruss::commitState() { // Commit the material return theMaterial->commitState(); } int CorotTruss::revertToLastCommit() { // Revert the material return theMaterial->revertToLastCommit(); } int CorotTruss::revertToStart() { // Revert the material to start return theMaterial->revertToStart(); } int CorotTruss::update(void) { // Nodal displacements const Vector &end1Disp = end1Ptr->getTrialDisp(); const Vector &end2Disp = end2Ptr->getTrialDisp(); // Initial offsets d21[0] = Lo; d21[1] = 0.0; d21[2] = 0.0; // Update offsets in basic system due to nodal displacements for (int i = 0; i < numDIM; i++) { d21[0] += R(0,i)*(end2Disp(i)-end1Disp(i)); d21[1] += R(1,i)*(end2Disp(i)-end1Disp(i)); d21[2] += R(2,i)*(end2Disp(i)-end1Disp(i)); } // Compute new length Ln = d21[0]*d21[0] + d21[1]*d21[1] + d21[2]*d21[2]; Ln = sqrt(Ln); // Compute engineering strain double strain = (Ln-Lo)/Lo; // Set material trial strain return theMaterial->setTrialStrain(strain); } const Matrix & CorotTruss::getTangentStiff(void) { static Matrix kl(3,3); // Material stiffness // // Get material tangent double EA = A*theMaterial->getTangent(); EA /= (Ln*Ln*Lo); int i,j; for (i = 0; i < 3; i++) for (j = 0; j < 3; j++) kl(i,j) = EA*d21[i]*d21[j]; // Geometric stiffness // // Get material stress double q = A*theMaterial->getStress(); double SA = q/(Ln*Ln*Ln); double SL = q/Ln; for (i = 0; i < 3; i++) { kl(i,i) += SL; for (j = 0; j < 3; j++) kl(i,j) -= SA*d21[i]*d21[j]; } // Compute R'*kl*R static Matrix kg(3,3); kg.addMatrixTripleProduct(0.0, R, kl, 1.0); Matrix &K = *theMatrix; K.Zero(); // Copy stiffness into appropriate blocks in element stiffness int numDOF2 = numDOF/2; for (i = 0; i < numDIM; i++) { for (j = 0; j < numDIM; j++) { K(i,j) = kg(i,j); K(i,j+numDOF2) = -kg(i,j); K(i+numDOF2,j) = -kg(i,j); K(i+numDOF2,j+numDOF2) = kg(i,j); } } return *theMatrix; } const Matrix & CorotTruss::getSecantStiff(void) { return this->getTangentStiff(); } const Matrix & CorotTruss::getDamp(void) { theMatrix->Zero(); return *theMatrix; } const Matrix & CorotTruss::getMass(void) { Matrix &Mass = *theMatrix; Mass.Zero(); int numDOF2 = numDOF/2; for (int i = 0; i < numDIM; i++) { Mass(i,i) = M; Mass(i+numDOF2,i+numDOF2) = M; } return *theMatrix; } void CorotTruss::zeroLoad(void) { return; } int CorotTruss::addLoad(const Vector &addP) { return 0; } int CorotTruss::addInertiaLoadToUnbalance(const Vector &accel) { return 0; } const Vector & CorotTruss::getResistingForce() { // Get material stress double SA = A*theMaterial->getStress(); SA /= Ln; static Vector ql(3); ql(0) = d21[0]*SA; ql(1) = d21[1]*SA; ql(2) = d21[2]*SA; static Vector qg(3); qg.addMatrixTransposeVector(0.0, R, ql, 1.0); Vector &P = *theVector; P.Zero(); // Copy forces into appropriate places int numDOF2 = numDOF/2; for (int i = 0; i < numDIM; i++) { P(i) = -qg(i); P(i+numDOF2) = qg(i); } return *theVector; } const Vector & CorotTruss::getResistingForceIncInertia() { Vector &P = *theVector; P = this->getResistingForce(); if (M != 0.0) { const Vector &accel1 = end1Ptr->getTrialAccel(); const Vector &accel2 = end2Ptr->getTrialAccel(); int numDOF2 = numDOF/2; for (int i = 0; i < numDIM; i++) { P(i) += M*accel1(i); P(i+numDOF2) += M*accel2(i); } } return *theVector; } int CorotTruss::sendSelf(int commitTag, Channel &theChannel) { return -1; } int CorotTruss::recvSelf(int commitTag, Channel &theChannel, FEM_ObjectBroker &theBroker) { return -1; } int CorotTruss::displaySelf(Renderer &theViewer, int displayMode, float fact) { // ensure setDomain() worked if (Ln == 0.0) return 0; // first determine the two end points of the CorotTruss based on // the display factor (a measure of the distorted image) // store this information in 2 3d vectors v1 and v2 const Vector &end1Crd = end1Ptr->getCrds(); const Vector &end2Crd = end2Ptr->getCrds(); const Vector &end1Disp = end1Ptr->getDisp(); const Vector &end2Disp = end2Ptr->getDisp(); static Vector v1(3); static Vector v2(3); for (int i = 0; i < numDIM; i++) { v1(i) = end1Crd(i)+end1Disp(i)*fact; v2(i) = end2Crd(i)+end2Disp(i)*fact; } return theViewer.drawLine(v1, v2, 1.0, 1.0); } void CorotTruss::Print(ostream &s, int flag) { s << "\nCorotTruss, tag: " << this->getTag() << endl; s << "\tConnected Nodes: " << connectedExternalNodes; s << "\tSection Area: " << A << endl; s << "\tUndeformed Length: " << Lo << endl; s << "\tCurrent Length: " << Ln << endl; s << "\tRotation matrix: " << endl; if (theMaterial) { s << "\tAxial Force: " << A*theMaterial->getStress() << endl; s << "\tUniaxialMaterial, tag: " << theMaterial->getTag() << endl; theMaterial->Print(s,flag); } } Response* CorotTruss::setResponse(char **argv, int argc, Information &eleInfo) { // force (axialForce) if (strcmp(argv[0],"force") == 0 || strcmp(argv[0],"forces") == 0 || strcmp(argv[0],"axialForce") == 0) return new ElementResponse(this, 1, 0.0); else if (strcmp(argv[0],"defo") == 0 || strcmp(argv[0],"deformations") == 0 || strcmp(argv[0],"deformation") == 0) return new ElementResponse(this, 2, 0.0); // a material quantity else if (strcmp(argv[0],"material") == 0) return theMaterial->setResponse(&argv[1], argc-1, eleInfo); else return 0; } int CorotTruss::getResponse(int responseID, Information &eleInfo) { switch (responseID) { case 1: return eleInfo.setDouble(A * theMaterial->getStress()); case 2: return eleInfo.setDouble(Lo * theMaterial->getStrain()); default: return 0; } }

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