TR.13.1 Plate and Shell Element Incidence Specification
This set of commands is used to specify elements by defining the connectivity between joints. REPEAT
and REPEAT ALL
commands are available to facilitate generation of repetitive patterns.
The element incidences must be defined such that the model developed represents one single structure only, not two or more separate structures. STAAD.Pro is capable of detecting multiple structures automatically
General Format
ELEMENT INCIDENCES (SHELL)
i1 nA nB nC (nD) ( TO i2 i3 i4 )
REPEAT n ei ji
REPEAT ALL n ei ji
Description
ELEMENT INCIDENCES SHELL
must be provided immediately after
MEMBER INCIDENCES
(if any) are specified.
Parameter | Definition |
---|---|
i1 | Element number (any number up to six digits). If |
nA … nD |
Note: Refer to G.5.1 Plate and Shell Elements for additional details on element incidences.
Nodes nA … nD correspond to IJKL
vertices. Clockwise or counterclockwise node (i.e., joint) numbers which
represent the element connectivity.
Note:
nD is not needed for triangular (3-noded) elements.
|
The following parameters are needed if elements are to be generated:
Parameter | Definition |
---|---|
i2 | Last element number to which elements are generated. |
i3 | Element number increment by which elements are generated. Defaults to 1 if omitted. |
i4 | Joint number increment which will be added to incident joints. Defaults to 1 if omitted. |
REPEAT
command causes the previous line of input to be
repeated n number of times with specified element and joint increments.
The REPEAT ALL
command functions similar to the REPEAT
command, except that it repeats all previously specified input back to the most recent
REPEAT ALL
command; or to the beginning of the specification if no
previous REPEAT ALL
command had been issued. Use REPEAT ALL 0 0
0
to start a set of elements that will be repeated if you don’t want to repeat
back to the last REPEAT ALL
.The following data is needed if
REPEAT
or REPEAT ALL
commands are used to generate
elements:
Parameter | Definition |
---|---|
n | Number of times repeat is to be carried out. |
ei | Element number increment. |
ji | Joint number increment. |
The PRINT ELEMENT INFORMATION
command may be used to verify the element
incidences provided or generated by REPEAT
and REPEAT
ALL
commands. Refer to
Element Information for details.
Example 1: Single Elements
Individual element incidences:
ELEMENT INCIDENCE
* Four nodes designates a quadrilateral element
1 1 2 7 6
* Three nodes designates a triangular element
2 3 4 8
Example 2: Generate Multiple Elements
ELEMENT INCIDENCE
* Generate quadrilateral elements
3 8 9 11 10 TO 8 1 2
* Note: here, the element and joint increments have been specified
* Generate triangular elements
9 1 3 7 TO 14
* Note: here, the element and joint increments default to 1