CONN2

Connector ElementCONN2 lets you connect NLFE elements that have structural discontinuity.

Format

<CONN2
       id       = "integer"
       g1       = "integer"
       g2       = "integer"
       conn     = "string"      
      [graph    = "integer"]/>

Attributes

id: Unique identification number.
g1: First grid identification number.
g2: Second grid identification number, $g1 \neq g2$ .
conn: String containing at most 12 characters that describe the connection between the coordinates. 4
graph: Post-processing flag. Use this flag to control how this element is displayed in the animation H3D. Default for graph is 0. See 6.

Example

The example demonstrates the definition of a CONN2 element.

<CONN2 id="900" g1="521" g2="12" conn="TTTTTTTTTTTT"/>

Comments

This type of element is used to connect between elements that have structural discontinuity. Each connector element of type CONN2 has a unique identification number with respect to other connector elements of the same type.
Grid 1 and 2 do not need to be co-incident, as in an offset between the two is allowed. In addition, the gradient vectors of Grid 1 do not need to be aligned with Grid 2.
Grid 2 is required to have full 12 generalized coordinates associated with it. CONN2 establishes up to 12 kinematic relationships of Grid 1 coordinates with respect to Grid 2 coordinates:
(1)
$\begin{array}{l} r_{1} = r_{2} + c_{0}^{1} * r x_{2} + c_{0}^{2} * r y_{2} + c_{0}^{3} * r z_{2} \\ r x_{1} = c_{1}^{1} * r x_{2} + c_{1}^{2} * r y_{2} + c_{1}^{3} * r z_{2} \\ r y_{1} = c_{2}^{1} * r x_{2} + c_{2}^{2} * r y_{2} + c_{2}^{3} * r z_{2} \\ r z_{1} = c_{3}^{1} * r x_{2} + c_{3}^{2} * r y_{2} + c_{3}^{3} * r z_{2} \end{array}$

The constant coefficients in the equations above are automatically computed by MotionSolve based on the model positions of Grid 1 and Grid 2.
The letter 'T' in attribute conn indicates the particular kinematic relationship that will be imposed by MotionSolve at all times during the simulation. The attribute conn can have up to 12 'T' (True) or 'F' (False) characters. For example, if conn="TTTFFFFFFFFF", the first three conditions in the previous comment will be imposed and the rest of the conditions will not be imposed by MotionSolve.
The default for the attribute conn is "FFFFFFFFFFFF". Further, conn="TTT" is equivalent to conn="TTTFFFFFFFFF". If the number of characters in the attribute conn is more than the number of generalized coordinates of either Grid 1 or 2, any character which does not have corresponding coordinates in either Grid 1 or 2 will be ignored.
The graph attribute controls how this connector element is displayed in the animation H3D:
- graph ="0" implies the CONN2 element is not represented in the H3D
- graph ="1" impliesthat a line connecting the two nodes will be displayed for this element.