Method formElementResidual

SRC/analysis/integrator/AlphaOS.cpp:520–553

int AlphaOS::formElementResidual(void)
{
    // calculate Residual Force
    AnalysisModel *theModel = this->getAnalysisModel();
    LinearSOE *theSOE = this->getLinearSOE();
    
    // loop through the FE_Elements and add the residual
    FE_Element *elePtr;
    FE_EleIter &theEles = theModel->getFEs();
    while((elePtr = theEles()) != 0)  {
        if (theSOE->addB(elePtr->getResidual(this), elePtr->getID()) < 0)  {
            opserr << "WARNING AlphaOS::formElementResidual() -";
            opserr << " failed in addB for ID " << elePtr->getID();
            return -1;
        }
        if (alpha < 1.0)  {
            if (statusFlag == CURRENT_TANGENT)  {
                if (theSOE->addB(elePtr->getK_Force(*Ut-*Upt), elePtr->getID(), alpha-1.0) < 0)  {
                    opserr << "WARNING AlphaOS::formElementResidual() -";
                    opserr << " failed in addB for ID " << elePtr->getID();
                    return -2;
                }
            } else if (statusFlag == INITIAL_TANGENT)  {
                if (theSOE->addB(elePtr->getKi_Force(*Ut-*Upt), elePtr->getID(), alpha-1.0) < 0)  {
                    opserr << "WARNING AlphaOS::formElementResidual() -";
                    opserr << " failed in addB for ID " << elePtr->getID();
                    return -2;
                }
            }
        }
    }
    
    return 0;
}