/SECT

Block Format Keyword

/SECT - Sections

Description

A section is a set of nodes and a set of elements.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/SECT/sect_ID/unit_ID
sect_title
node_ID1	node_ID2	node_ID3	grnod_ID	ISAVE	Frame_ID
file_name
grbric_ID		grshel_ID	grtrus_ID	grbeam_ID	grsprg_ID	grtria_ID	Ninter		Iframe

Input read only if Ninter > 0

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
int_ID1	int_ID2	int_ID3	int_ID4	int_ID5	int_ID6	int_ID7	int_ID8	int_ID9	int_ID10

Field	Contents	SI Unit Example
sect_ID	Section identifier (Integer, maximum 10 digits)
unit_ID	Optional unit identifier (Integer, maximum 10 digits)
sect_title	Section title (Character, maximum 100 characters)
node_ID1	Node identifier N1 (Integer)
node_ID2	Node identifier N2 (Integer)
node_ID3	Node identifier N3 (Integer)
grnod_ID	Node group identifier (Integer)
ISAVE	Saving the data flag (Integer) = 0: Do not save = 1: Displacements are saved in the section cut file "file_name" = 2: same as 1, in addition the section resultant force and moment components are saved in the section cut file. = 100: The data contained in the section cut file "file_name" is read as input for the calculation. = 101: same as 100, in addition the difference between section resultant force and moment between full and cut model are calculated (Comments 5 through 8).
Frame_ID	Moving frame identifier (Comment 20) (Integer)
	Time step for saving the data (Real)
	Coefficient for filtering ( < 1) (Real)
file_name	Root name of the file which contains the flag output. The extension for this file is nameSC01 (Character, maximum 100 characters)
grbric_ID	Brick group identifier (Integer)
grshel_ID	Shell group identifier (Integer)
grtrus_ID	Truss group identifier (Integer)
grbeam_ID	Beam group identifier (Integer)
grsprg_ID	Spring group identifier (Integer)
grtriag_ID	Triangle group identifier (Integer)
Ninter	Number of interfaces (Integer)
Iframe	Computing the skew center local skew is the skew flag defined by node_ID1, node_ID2, and node_ID3 (see figure in Comment 14) (Integer) The center C is given in the local skew: = 0: the origin of the local skew (C0) = 1: the geometrical center of the section (C1) = 2: the CoG of the section (C2) = 3: point o(0,0,0) is the center of the local skew The center C is given in the global skew: = 10: the origin of the global skew (C0) = 11: the geometrical center of the section (C1) = 12: the CoG of the section (C2) = 13: point o(0,0,0) is the center of the global skew
int_ID1, int_ID2, ..., int_IDn	Optional interface identifiers, if Ninter > 0 (Integer)

1.	Resulting forces and moments acting on these sections will be stored in the Time History file.

2.	You can save force and moment in an output file. This output could be used as input for another calculation.

3.	Nodes node_ID1 and node_ID2 define the local X-axis of the section.

4.	Nodes node_ID1, node_ID2 and node_ID3 define the local plane XY of the section.

5.	Flag ISAVE is used for saving data in the SC01 file for the cut methodology.

It is recommended to set ISAVE =0 if no cut methodology is intended, since performance may be decreased and memory for RADIOSS Engine will be increased.

6.	If ISAVE = 1, displacement of section nodes are saved in the file "file_nameSC01" at a frequency t.

If ISAVE =2, the components of resultant section force and moments are also saved in file "file_nameSC01".

7.	If ISAVE = 100, displacements of section nodes are read from the file "file_nameSC01".

If ISAVE =101, the components of resultant section force and moments are also read from the file "file_nameSC01"

The displacements are filtered according to the following relations:

y+ = x + (1-)y

with,

for filtering -3dB

for filtering -6dB

Where, T is the filtering period, in general, T = 10t.

Typical use .

Parameters ISAVE=1, 2, 100, and 101 are used for so-called submodeling technique. In this case a full model is run with ISAVE=1 or 2 in order to save displacement or displacement and resultant section forces/moments in file "file_nameSC01". Afterwards the cut model is created where displacement of the nodes are read from the file with ISAVE=101 or 102 option. If ISAVE=2 is used in the full model and ISAVE=101 is used in the cut model, then RADIOSS may output the difference between resultant section forces and moments in full and cut model in the section (/TH/SECTIO).

9.	Moments are computed with respect to the section center defined by the parameter Iframe (see figure in Comment 14) and expressed in the local section frame.

10.	Normal force is the component normal to the XY plane of the section. Tangential force is the component in the plane of the section.

In plot file FNX, FNY, FNZ, FTX, FTY, and FTZ are respectively the components of normal and tangential forces in the global frame (see figure below for the definition of the local frame).

11.	Moments calculation if Iframe = 0, 1, 2 or 3.

clip0125

12.	Moments calculation if Iframe = 10, 11, 12 or 13.

clip0126

13.	Forces and moments calculation.

clip0127

14.	Local reference frame (Ox and Oy):

clip0128

15.	The center C0 is given by the nodes: node_ID1, node_ID2 and node_ID3.

16.	The center C1 is the geometric center of the section nodes:

where, n = nodes

17.	The center C2 is the center of gravity of the section nodes:

18.	The center C3 is the node with coordinates (0, 0, 0) in the global skew.

19.	Frame had to be a moving frame (defined with 3 nodes).

20.	If Frame_ID ≠ 0, if N1, N2, N3 equal zero, local skew of the section is built with nodes of the frame.

21.	If Frame_ID ≠ 0, the set of node is created automatically by intersecting the (oXY) plane of the frame with the sets of elements.

The set of node contains nodes of intersected elements which are upside (+Z direction) and inside the (oXY) plane of the frame. The recalculated sets of elements contain elements cut by the (oXY) plane of the frame.

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/SECT

/SECT

See Also: