Method commitSensitivity

SRC/element/truss/TrussSection.cpp:1504–1618

}

int
TrussSection::commitSensitivity(int gradIndex, int numGrads)
{
	// Initial declarations
	int i; 
	double strainSensitivity, temp1, temp2;

	// Displacement difference between the two ends
	double strain = this->computeCurrentStrain();
	double dLength = strain*L;

	// Displacement sensitivity difference between the two ends
	double sens1;
	double sens2;
	double dSensitivity = 0.0;
	for (i=0; i<dimension; i++){
	  sens1 = theNodes[0]->getDispSensitivity(i+1, gradIndex);
	  sens2 = theNodes[1]->getDispSensitivity(i+1, gradIndex);
	  dSensitivity += (sens2-sens1)*cosX[i];
	}

	strainSensitivity = dSensitivity/L;

	// Check if a nodal coordinate is random
	int nodeParameterID0 = theNodes[0]->getCrdsSensitivity();
	int nodeParameterID1 = theNodes[1]->getCrdsSensitivity();
	if (nodeParameterID0 != 0 || nodeParameterID1 != 0) {

	  double dx = L*cosX[0];
	  double dy = L*cosX[1];
	  //double dz = L*cosX[2];

		// Compute derivative of transformation matrix (assume 4 dofs)
		double dcosXdh[3];

		if (nodeParameterID0 == 1) { // here x1 is random
			temp1 = (-L+dx*dx/L)/(L*L);
			temp2 = dx*dy/(L*L*L);
			//dtdh(0) = -temp1;
			//dtdh(1) = -temp2;
			//dtdh(2) = temp1;
			//dtdh(3) = temp2;
			dcosXdh[0] = temp1;
			dcosXdh[1] = temp2;
			dcosXdh[2] = 0.0;
		}
		if (nodeParameterID0 == 2) { // here y1 is random
			temp1 = (-L+dy*dy/L)/(L*L);
			temp2 = dx*dy/(L*L*L);
			//dtdh(0) = -temp2;
			//dtdh(1) = -temp1;
			//dtdh(2) = temp2;
			//dtdh(3) = temp1;
			dcosXdh[0] = temp2;
			dcosXdh[1] = temp1;
			dcosXdh[2] = 0.0;
		}