Selection of Objects in Tosca Structure.gui

Object Lists

In SIMULIA Tosca Structure, a list is created for most object types. At the beginning each object list is loaded with all the data that is read in by the FE interface, for example, the list of elements contains all elements from the first input file linked to the optimization task. When an object is selected, the selected object is added to the corresponding list. Selection lists can be used as selection criteria.

The following types of objects have their own lists and can be selected using the command SELECT:

• Coordinate Systems (CS)
• Elements (ELEM)
• Element groups (ELGR)
• Nodes (NODE)
• Node groups (NDGR)
• Element types (ETYPE, see Optimizable Element Types)
• Element properties (EPROP)
• Materials (MAT)
• Solids (SOLID)

Selection Types

Every SELECT command refers to one object type. The user must define whether the selected objects should be added to the existing object list (ADD) or removed (UNSELECT) or whether the selection list should be reset (SELECT). In addition, it is possible to keep only the actually selected objects of an existing selection list (RESELECT). All objects of the corresponding type can be registered in the selection list (ALL) or the selection list can be emptied (NONE). It is also possible to invert (INVERT) the content of the selection list. Depending on the selection type, existing selection lists can be extended or varied as shown in the following table:

Shortcut	Type	Description
S	Select	Initialization and New Selection.
R	Reselect	Selection of a subset from a selection list.
A	Add	Add objects to current selection list.
U	Unselect	Remove objects from current selection list.
ALL	Select all	Select all objects of the object type.
NONE	Select none	Empty selection list.
INV	Invert	Invert: Reverse selected and nonselected objects of the object type.

The following figure shows the selection lists and selection criteria:

Selection Lists and Selection Criteria

Selection Criteria

Almost all objects can be added to a selection list using numbers or names. For nodes and elements a variety of selection criteria exists as shown in the following table. For example, it is possible to select elements by their element property or material number defined in the analysis file. Thus element and node numbers do not must be explicitly known by the user.

Selection lists are useful tools that help the user to quickly define element and node lists. Selection lists are required for group definitions.

		Selection criteria
		NAME	NR.	CS	ELGR	NDGR	ETYP	EPROP	MAT	SOLID
Selection lists	CS	X
	ELGR	X
	NDGR	X
	ETYP	X
	EPROP		X
	MAT		X
	SOLID	X
	NODE		X	X		X			X	X
	ELEM		X		X		X	X

Examples

The following example serves to illustrate the effect of the selection commands. Each step is accompanied by a description of how the selection lists change.

The aim of this detailed example is to select a node group by list entries for which various assignments are applied (for example, nodes to elements, element to element properties).

The following steps are taken:

• Direct selection of elements by specifying the element numbers (in the example: elements 1, 3, 5).
• Selection of elements using element properties (in the example: element properties 3 and 5).
• Selection of the nodes associated with the actually selected elements.

Step 1: Select element numbers directly:

Elements can be selected directly by entering the element number:

SELECT, ELEM, S, ELEM, 1, 5, 2

By specifying the list name “ELEM”, the element list is addressed. The selection operator “S” initializes the element list (SELECT). The element numbers are directly specified as selection criterion (elements 1 to 5 with increments of 2). The elements 1, 3 and 5 are selected directly with their numbers and written into the element list as can be seen in the following table. All other lists remain unchanged.

List	List entries
ELEM	1, 3, 5

Step 2: Element Selection using Element Properties

The element list should be extended to include elements with the properties 3 or 5 as can be seen in the following table.

• First, the element properties 3 and 5 are added to the element property list. It is also possible to use increments.

  SELECT, EPROP, S, EPROP, 3,5,2
  
  

  The EPROP list is addressed. The selection operator “S” initializes the element property list. The ELEM list remains unchanged:

List	List entries
ELEM	1, 3, 5
EPROP	3, 5

• Now all elements with element properties that are currently in the element property list should be added to the already existing element list.

  SELECT, ELEM, A, EPROP
  
  

  The element list is addressed. The operator “A” (ADD) adds elements to the existing element list where the added elements have properties that are specified in the element property list as shown in the following table:

List	List entries
ELEM	1, 3, 5; and all elements with the element properties 3 and 5
EPROP	3, 5

Step 3: Select Nodes

In this step all nodes that belong to the selected elements are added to the node list. The element list is used as a selection criterion for nodes:

SELECT, NODE, S, ELEM

The node list is addressed and initialized. All nodes of the elements currently in the element list are included in the node list as shown in the following table:

List	List entries
ELEM	1, 3, 5; and all elements with the element properties 3 and 5
EPROP	3, 5
NODES	all nodes of the elements in the element list

Selection of elements by their material numbers or element types can also be carried out this way (Solver Specific Features).

Remarks

1. To use the selection possibilities for element types, materials and coordinates in SIMULIA Tosca Structure, all quantities must previously be defined and assigned in the FE analysis file.
2. Upon loading the analysis model, all loaded objects (nodes, elements, coordinate systems, materials, element types, element properties) are written into the corresponding lists. Initially, the lists “SOLID”, “ELGR” and “NDGR” are empty.