| 1669 | |
| 1670 | |
| 1671 | void TwoNodeLink::addPDeltaStiff(Matrix &kLocal, const Vector& qBasic) |
| 1672 | { |
| 1673 | int dirID; |
| 1674 | double N = 0.0; |
| 1675 | |
| 1676 | // get axial force |
| 1677 | for (int i=0; i<numDIR; i++) { |
| 1678 | if ((*dir)(i) == 0) |
| 1679 | N = qBasic(i); |
| 1680 | } |
| 1681 | |
| 1682 | if (N != 0.0) { |
| 1683 | for (int i=0; i<numDIR; i++) { |
| 1684 | dirID = (*dir)(i); // direction 0 to 5; |
| 1685 | |
| 1686 | // switch on dimensionality of element |
| 1687 | switch (elemType) { |
| 1688 | case D2N4: |
| 1689 | if (dirID == 1) { |
| 1690 | double NoverL = N/L; |
| 1691 | NoverL *= 1.0-Mratio(2)-Mratio(3); |
| 1692 | kLocal(1,1) += NoverL; |
| 1693 | kLocal(1,3) -= NoverL; |
| 1694 | kLocal(3,1) -= NoverL; |
| 1695 | kLocal(3,3) += NoverL; |
| 1696 | } |
| 1697 | break; |
| 1698 | case D2N6: |
| 1699 | if (dirID == 1) { |
| 1700 | double NoverL = N/L; |
| 1701 | NoverL *= 1.0-Mratio(2)-Mratio(3); |
| 1702 | kLocal(1,1) += NoverL; |
| 1703 | kLocal(1,4) -= NoverL; |
| 1704 | kLocal(4,1) -= NoverL; |
| 1705 | kLocal(4,4) += NoverL; |
| 1706 | } |
| 1707 | else if (dirID == 2) { |
| 1708 | kLocal(2,1) -= Mratio(2)*N; |
| 1709 | kLocal(2,4) += Mratio(2)*N; |
| 1710 | kLocal(5,1) -= Mratio(3)*N; |
| 1711 | kLocal(5,4) += Mratio(3)*N; |
| 1712 | } |
| 1713 | break; |
| 1714 | case D3N6: |
| 1715 | if (dirID == 1) { |
| 1716 | double NoverL = N/L; |
| 1717 | NoverL *= 1.0-Mratio(2)-Mratio(3); |
| 1718 | kLocal(1,1) += NoverL; |
| 1719 | kLocal(1,4) -= NoverL; |
| 1720 | kLocal(4,1) -= NoverL; |
| 1721 | kLocal(4,4) += NoverL; |
| 1722 | } |
| 1723 | else if (dirID == 2) { |
| 1724 | double NoverL = N/L; |
| 1725 | NoverL *= 1.0-Mratio(0)-Mratio(1); |
| 1726 | kLocal(2,2) += NoverL; |
| 1727 | kLocal(2,5) -= NoverL; |
| 1728 | kLocal(5,2) -= NoverL; |