Method update

SRC/element/zeroLength/ZeroLength.cpp:791–835

int
ZeroLength::update(void)
{
    double strain;
    double strainRate;

    // get trial displacements and take difference
    const Vector& disp1 = theNodes[0]->getTrialDisp();
    const Vector& disp2 = theNodes[1]->getTrialDisp();
    Vector  diff  = disp2-disp1;
    const Vector& vel1  = theNodes[0]->getTrialVel();
    const Vector& vel2  = theNodes[1]->getTrialVel();
    Vector  diffv = vel2-vel1;
    
    if (d0 != 0)
      diff -= *d0;

    if (v0 != 0)
      diffv -= *v0;
    
    // loop over 1d materials
    
    //    Matrix& tran = *t1d;
    int ret = 0;
    for (int mat=0; mat<numMaterials1d; mat++) {
	// compute strain and rate; set as current trial for material
	strain     = this->computeCurrentStrain1d(mat,diff );
        strainRate = this->computeCurrentStrain1d(mat,diffv);
	ret += theMaterial1d[mat]->setTrialStrain(strain,strainRate);
	if (useRayleighDamping == 2) {
	  ret += theMaterial1d[mat+numMaterials1d]->setTrialStrain(strainRate);	  
	}
    }

  if (theDamping)
  {
    Vector q(numMaterials1d);
    for (int i = 0; i < numMaterials1d; ++i)
      q(i) = theMaterial1d[i]->getStress();
    
    theDamping->update(q);
  }

    return ret;
}

const Matrix &
ZeroLength::getTangentStiff(void)