Keyword type: model definition
This option is used to define the design variables for a sensitivity study. The parameter TYPE is required and can take the value COORDINATE (with or without the extra appendix NO REGION) or ORIENTATION. In case of COORDINATE a second line is needed to define the nodes whose coordinates are to be changed. These nodes should be part of the surface of the structure (a change in position of nodes internal to the structure does not change the geometry). They will be varied in a direction locally orthogonal to the structure (in-surface motions do not change the geometry). If the type is set to COORDINATE NO REGION the normal is calculated based on all external faces adjacent to the node. If NO REGION is omitted, the normal is calculated based on those external faces adjacent to the node which contain a minimum number of design variables, e.g. 5 for a 8-noded face. This assures that faces adjacent to a design region are not taken into account in the calculation of the normal. In the case of ORIENTATION the sensitivity of all orientations expressed by *ORIENTATION cards is calculated successively.
This keywork card should only occur once in the input deck. If it occurs more than once only the first occurrence is taken into account.
First line:
Following line if TYPE=COORDINATE:
Example: *DESIGN VARIABLES,TYPE=COORDINATE N1
defines the set N1 as the node set containing the design variables.
Example files: sensitivity_I.