const Vector &
SSPquadUP::getResistingForceIncInertia()
{
// terms stemming from acceleration
const Vector &accel1 = theNodes[0]->getTrialAccel();
const Vector &accel2 = theNodes[1]->getTrialAccel();
const Vector &accel3 = theNodes[2]->getTrialAccel();
const Vector &accel4 = theNodes[3]->getTrialAccel();
// compute current resisting force
this->getResistingForce();
// compute mass matrix
this->getMass();
Vector a(12);
a(0) = accel1(0);
a(1) = accel1(1);
a(2) = accel1(2);
a(3) = accel2(0);
a(4) = accel2(1);
a(5) = accel2(2);
a(6) = accel3(0);
a(7) = accel3(1);
a(8) = accel3(2);
a(9) = accel4(0);
a(10) = accel4(1);
a(11) = accel4(2);
mInternalForces.addMatrixVector(1.0, mMass, a, 1.0);
// terms stemming from velocity
const Vector &vel1 = theNodes[0]->getTrialVel();
const Vector &vel2 = theNodes[1]->getTrialVel();
const Vector &vel3 = theNodes[2]->getTrialVel();
const Vector &vel4 = theNodes[3]->getTrialVel();
Vector v(12);
v(0) = vel1(0);
v(1) = vel1(1);
v(2) = vel1(2);
v(3) = vel2(0);
v(4) = vel2(1);
v(5) = vel2(2);
v(6) = vel3(0);
v(7) = vel3(1);
v(8) = vel3(2);
v(9) = vel4(0);
v(10) = vel4(1);
v(11) = vel4(2);
// compute damping matrix
this->getDamp();
mInternalForces.addMatrixVector(1.0, mDamp, v, 1.0);
return mInternalForces;
}
const Vector&
FourNodeQuadUP::getResistingForceIncInertia()
{
int i, j, k;
const Vector &accel1 = nd1Ptr->getTrialAccel();
const Vector &accel2 = nd2Ptr->getTrialAccel();
const Vector &accel3 = nd3Ptr->getTrialAccel();
const Vector &accel4 = nd4Ptr->getTrialAccel();
static double a[12];
a[0] = accel1(0);
a[1] = accel1(1);
a[2] = accel1(2);
a[3] = accel2(0);
a[4] = accel2(1);
a[5] = accel2(2);
a[6] = accel3(0);
a[7] = accel3(1);
a[8] = accel3(2);
a[9] = accel4(0);
a[10] = accel4(1);
a[11] = accel4(2);
// Compute the current resisting force
this->getResistingForce();
//opserr<<"K "<<P<<endln;
// Compute the mass matrix
this->getMass();
for (i = 0; i < 12; i++) {
for (j = 0; j < 12; j++)
P(i) += K(i,j)*a[j];
}
//opserr<<"K+M "<<P<<endln;
// dynamic seepage force
/*for (i = 0, k = 0; i < 4; i++, k += 3) {
// loop over integration points
for (j = 0; j < 4; j++) {
P(i+2) -= rho*dvol[j]*(shp[2][i][j]*a[k]*perm[0]*shp[0][i][j]
+shp[2][i][j]*a[k+1]*perm[1]*shp[1][i][j]);
}
}*/
//opserr<<"K+M+fb "<<P<<endln;
const Vector &vel1 = nd1Ptr->getTrialVel();
const Vector &vel2 = nd2Ptr->getTrialVel();
const Vector &vel3 = nd3Ptr->getTrialVel();
const Vector &vel4 = nd4Ptr->getTrialVel();
a[0] = vel1(0);
a[1] = vel1(1);
a[2] = vel1(2);
a[3] = vel2(0);
a[4] = vel2(1);
a[5] = vel2(2);
a[6] = vel3(0);
a[7] = vel3(1);
a[8] = vel3(2);
a[9] = vel4(0);
a[10] = vel4(1);
a[11] = vel4(2);
this->getDamp();
for (i = 0; i < 12; i++) {
for (j = 0; j < 12; j++) {
P(i) += K(i,j)*a[j];
}
}
//opserr<<"final "<<P<<endln;
return P;
}
