const Matrix &
PileToe3D::getTangentStiff(void)
{
//double mPi = 4.0*atan(1);
const double mPi = 3.1415926535897;
double mArea = mPi* mRadius*mRadius;
double mII = mPi*mRadius*mRadius*mRadius*mRadius/4.0;
// initialize Kt
mTangentStiffness.Zero();
/*
mTangentStiffness(0,0) = mSubgradeCoeff*mArea;
mTangentStiffness(1,1) = mSubgradeCoeff*mArea;
mTangentStiffness(2,2) = mSubgradeCoeff*mArea;
mTangentStiffness(3,3) = mSubgradeCoeff*mII;
mTangentStiffness(4,4) = mSubgradeCoeff*mII;
mTangentStiffness(5,5) = mSubgradeCoeff*mII;
mTangentStiffness(0,0) = mSubgradeCoeff*mArea;
mTangentStiffness(4,4) = mSubgradeCoeff*mII;
mTangentStiffness(5,5) = mSubgradeCoeff*mII;
*/
mTangentStiffness(2,2) = mSubgradeCoeff*mArea;
mTangentStiffness(3,3) = mSubgradeCoeff*mII;
mTangentStiffness(4,4) = mSubgradeCoeff*mII;
return mTangentStiffness;
}
const Matrix &
SSPquadUP::getTangentStiff(void)
// this function computes the tangent stiffness matrix for the element
{
// solid phase stiffness matrix
GetSolidStiffness();
// assemble full element stiffness matrix [ K 0 ]
// comprised of K submatrix [ 0 0 ]
mTangentStiffness.Zero();
for (int i = 0; i < 4; i++) {
int I = 2*i;
int Ip1 = 2*i+1;
int II = 3*i;
int IIp1 = 3*i+1;
for (int j = 0; j < 4; j++) {
int J = 2*j;
int Jp1 = 2*j+1;
int JJ = 3*j;
int JJp1 = 3*j+1;
// contribution of solid phase stiffness matrix
mTangentStiffness(II,JJ) = mSolidK(I,J);
mTangentStiffness(IIp1,JJ) = mSolidK(Ip1,J);
mTangentStiffness(IIp1,JJp1) = mSolidK(Ip1,Jp1);
mTangentStiffness(II,JJp1) = mSolidK(I,Jp1);
}
}
return mTangentStiffness;
}
const Matrix &
BeamEndContact3D::getTangentStiff(void)
// this function computes the tangent stiffness matrix for the element
{
mTangentStiffness.Zero();
if (inContact) {
for (int i = 0; i <= 2; i++) {
mTangentStiffness(i,9) = mNormal(i);
mTangentStiffness(i+6,9) = -mNormal(i);
mTangentStiffness(9,i) = mNormal(i);
mTangentStiffness(9,i+6) = -mNormal(i);
}
mTangentStiffness(10,10) = 1.0;
mTangentStiffness(11,11) = 1.0;
} else {
mTangentStiffness(9,9) = 1.0;
mTangentStiffness(10,10) = 1.0;
mTangentStiffness(11,11) = 1.0;
}
return mTangentStiffness;
}
const Matrix &
BeamContact2D::getTangentStiff(void)
// this function computes the tangent stiffness matrix for the element
{
mTangentStiffness.Zero();
if (inContact) {
Matrix Cmat = theMaterial->getTangent();
double Css = Cmat(1,1);
double Csn = Cmat(1,2);
for (int i = 0; i < BC2D_NUM_DOF-2; i++) {
for (int j = 0; j < BC2D_NUM_DOF-2; j++) {
mTangentStiffness(i,j) = mBs(i)*mBs(j)*Css;
}
}
for (int i = 0; i < BC2D_NUM_DOF-2; i++) {
mTangentStiffness(8,i) = -mBn(i);
mTangentStiffness(i,8) = -mBn(i) + Csn*mBs(i);
}
mTangentStiffness(9,9) = 1.0;
} else {
mTangentStiffness(8,8) = 1.0;
mTangentStiffness(9,9) = 1.0;
}
return mTangentStiffness;
}
const Matrix &
BeamEndContact3Dp::getTangentStiff(void)
// this function computes the tangent stiffness matrix for the element
{
mTangentStiffness.Zero();
double tangentTerm;
if (inContact) {
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
tangentTerm = mPenalty*mNormal(i)*mNormal(j);
mTangentStiffness(i,j) = tangentTerm;
mTangentStiffness(i,6+j) = -tangentTerm;
mTangentStiffness(6+i,j) = -tangentTerm;
mTangentStiffness(6+i,6+j) = tangentTerm;
}
}
}
return mTangentStiffness;
}
const Matrix &
BeamContact2Dp::getTangentStiff(void)
// this function computes the tangent stiffness matrix for the element
{
mTangentStiffness.Zero();
if (inContact) {
Matrix Cmat = theMaterial->getTangent();
double Css = Cmat(1,1);
double Csn = Cmat(1,2);
for (int i = 0; i < BC2D_NUM_DOF; i++) {
for (int j = 0; j < BC2D_NUM_DOF; j++) {
mTangentStiffness(i,j) = mBs(i)*mBs(j)*Css - mPenalty*(Csn*mBs(i)*mBn(j) - mBn(i)*mBn(j));
}
}
}
return mTangentStiffness;
}
