Method newStep

SRC/analysis/integrator/KRAlphaExplicit.cpp:137–271

int KRAlphaExplicit::newStep(double _deltaT)
{
    updateCount = 0;
    
    if (beta == 0 || gamma == 0 )  {
        opserr << "WARNING KRAlphaExplicit::newStep() - error in variable\n";
        opserr << "gamma = " << gamma << " beta = " << beta << endln;
        return -1;
    }
    
    // get a pointer to the AnalysisModel
    AnalysisModel *theModel = this->getAnalysisModel();
    if (theModel == 0)  {
        opserr << "WARNING KRAlphaExplicit::newStep() - no AnalysisModel set\n";
        return -2;
    }
    
    // initialize the integration matrices
    if (_deltaT != deltaT) {
        // update time step increment
        deltaT = _deltaT;
        initAlphaMatrices = 1;
    }
    if (initAlphaMatrices)  {
        if (deltaT <= 0.0)  {
            opserr << "WARNING KRAlphaExplicit::newStep() - error in variable\n";
            opserr << "dT = " << deltaT << endln;
            return -3;
        }
        
        // get the LinearSOE and the ConvergenceTest so we can switch back later
        LinearSOE *theLinSOE = this->getLinearSOE();
        ConvergenceTest *theTest = this->getConvergenceTest();
        
        // set up the FullLinearSOE (needed to compute the alpha matrices)
        int size = theLinSOE->getNumEqn();
        FullGenLinSolver *theFullLinSolver = new FullGenLinLapackSolver();
        LinearSOE *theFullLinSOE = new FullGenLinSOE(size, *theFullLinSolver);
        if (theFullLinSOE == 0)  {
            opserr << "WARNING KRAlphaExplicit::newStep() - failed to create FullLinearSOE\n";
            return -4;
        }
        theFullLinSOE->setLinks(*theModel);
        
        // now switch the SOE to the FullLinearSOE
        this->IncrementalIntegrator::setLinks(*theModel, *theFullLinSOE, theTest);
        
        // get a pointer to the A matrix of the FullLinearSOE
        const Matrix *tmp = theFullLinSOE->getA();
        if (tmp == 0)  {
            opserr << "WARNING KRAlphaExplicit::newStep() - ";
            opserr << "failed to get A matrix of FullGeneral LinearSOE\n";
            return -5;
        }
        
        // calculate the integration parameter matrices
        c1 = beta*deltaT*deltaT;
        c2 = gamma*deltaT;