int
BeamEndContact3D::update(void)
// this function updates variables for an incremental step n to n+1
{
Vector disp_L(3);
Vector disp_a(6);
Vector rot_a(BEC3_NUM_DIM);
Vector omega(BEC3_NUM_DIM);
Matrix eMap(BEC3_NUM_DIM,BEC3_NUM_DIM);
// update beam node coordinates and rotations
disp_a = theNodes[0]->getTrialDisp();
for (int i = 0; i < 3; i++) {
mDcrd_a(i) = mIcrd_a(i) + disp_a(i);
rot_a(i) = disp_a(i+3);
}
// update slave node coordinates
mDcrd_s = mIcrd_s + theNodes[1]->getTrialDisp();
// update Lagrange multiplier value
disp_L = theNodes[2]->getTrialDisp();
mLambda = disp_L(0);
// update the normal vector
omega = rot_a - ((mNormal^rot_a)*mNormal);
// compute exponential map of skew(omega)
eMap = ExpMap(omega);
// compute the current normal vector
mNormal = eMap*mIniNormal;
// update gap
mGap = (mDcrd_s - mDcrd_a)^mNormal;
// update projection coordinate
mx_p = mDcrd_s - (mGap*mNormal);
// set the boolean release condition
should_be_released = (mLambda <= -mForceTol);
return 0;
}
int
BeamContact2Dp::update(void)
// this function updates variables for an incremental step n to n+1
{
double tensileStrength;
Vector a1(BC2D_NUM_DIM);
Vector b1(BC2D_NUM_DIM);
Vector a1_n(BC2D_NUM_DIM);
Vector b1_n(BC2D_NUM_DIM);
Vector disp_a(3);
Vector disp_b(3);
Vector disp_L(BC2D_NUM_DIM);
double rot_a;
double rot_b;
Vector x_c(BC2D_NUM_DIM);
// update slave node coordinates
mDcrd_s = mIcrd_s + theNodes[2]->getTrialDisp();
// update nodal coordinates
disp_a = theNodes[0]->getTrialDisp();
disp_b = theNodes[1]->getTrialDisp();
for (int i = 0; i < 2; i++) {
mDcrd_a(i) = mIcrd_a(i) + disp_a(i);
mDcrd_b(i) = mIcrd_b(i) + disp_b(i);
}
// compute incremental rotation from step n to step n+1
rot_a = disp_a(2) - mDisp_a_n(2);
rot_b = disp_b(2) - mDisp_b_n(2);
// get tangent vectors from last converged step
a1_n = Geta1();
b1_n = Getb1();
// linear update of tangent vectors
a1 = a1_n + rot_a*mEyeS*a1_n;
b1 = b1_n + rot_b*mEyeS*b1_n;
// update centerline projection coordinate
x_c = mDcrd_a*mShape(0) + a1*mLength*mShape(1) + mDcrd_b*mShape(2) + b1*mLength*mShape(3);
// update penetration function
mGap = (mNormal^(mDcrd_s - x_c)) - mRadius;
if (mGap < 0.0 && in_bounds) {
inContact = true;
} else {
mGap = 0.0;
inContact = false;
}
// update normal contact force
if (was_inContact) {
mLambda = mPenalty*mGap;
} else {
mLambda = 0.0;
}
// get tensile strength from contact material
tensileStrength = theMaterial->getTensileStrength();
// determine trial strain vector based on contact state
if (inContact) {
Vector strain(3);
double slip;
Vector c1n1(2);
Vector c2n1(2);
// tangent at the centerline projection in step n+1
c1n1 = mDshape(0)*mDcrd_a + mDshape(1)*mLength*ma_1 + mDshape(2)*mDcrd_b + mDshape(3)*mLength*mb_1;
// update vector c2 for step n+1
c2n1 = (mDcrd_s - x_c)/((mDcrd_s - x_c).Norm());
// update vector c2 for step n+1
c2n1(0) = -c1n1(1);
c2n1(1) = c1n1(0);
// compute the slip
slip = mg_xi^(mDcrd_s - x_c - mrho*c2n1);
// set the strain vector
strain(0) = mGap;
strain(1) = slip;
strain(2) = -mLambda;
theMaterial->setTrialStrain(strain);
} else {
Vector strain(3);
// set the strain vector
strain(0) = mGap;
strain(1) = 0.0;
strain(2) = -mLambda;
theMaterial->setTrialStrain(strain);
}
return 0;
}