3.1.8.2. PDelta Transformation
This command is used to construct the P-Delta Coordinate Transformation (PDeltaCrdTransf) object, which performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global coordinate system, considering second-order P-Delta effects.
For a two-dimensional problem:
- geomTransf PDelta $transfTag <-jntOffset $dXi $dYi $dXj $dYj>
For a three-dimensional problem:
- geomTransf PDelta $transfTag $vecxzX $vecxzY $vecxzZ <-jntOffset $dXi $dYi $dZi $dXj $dYj $dZj>
Argument |
Type |
Description |
|---|---|---|
$transfTag |
integer |
integer tag identifying transformation |
$vecxzX $vecxzY $vecxzZ |
float |
X, Y, and Z components of vecxz, the vector used to define the local x-z plane of the local-coordinate system. The local y-axis is defined by taking the cross product of the vecxz vector and the x-axis. These components are specified in the global-coordinate system X,Y,Z and define a vector that is in a plane parallel to the x-z plane of the local-coordinate system. These items need to be specified for the three-dimensional problem. |
$dXi $dYi $dZi |
float |
joint offset values – offsets specified with respect to the global coordinate system for element-end node i (optional, the number of arguments depends on the dimensions of the current model). |
$dXj $dYj $dZj |
float |
joint offset values – offsets specified with respect to the global coordinate system for element-end node j (optional, the number of arguments depends on the dimensions of the current model). |
Note
The element coordinate system and joint offset values are specified as in the Linear Transformation.