/ADMESH/SET

Block Format Keyword

/ADMESH/SET - Adaptive Meshing – Set for Adaptive Meshing

Description

Defines the criteria for adaptive meshing in parts. This keyword is not available for SPMD computation.

Format

Field	Contents	SI Unit Example
adset_ID	Set for adaptive meshing block identifier (Integer, maximum 10 digits)
adset_title	Set for adaptive meshing block name (Character, maximum 100 characters)
Angle Criterion	Angle criterion for mesh refinement (Comment 3) (Real)
Inilev	Initial level of refinement > 0: elements of the corresponding parts are divided, at time 0, up to the level equal to Inilev. (Integer)
Thkerr	Criterion based upon estimated thickness error (Comment 4) (Real)
ID1, ID2	IDs of parts declared for adaptive meshing within this set (Integer, maximum 10 per format)

1.	Several sets of parts may be declared for adaptivity, each using for instance, different angle criteria.

2.	A part declared for adaptivity can include 4-node shell elements or 3-node shell elements and use any shell element formulation; except DKT18 and DKT_S3 formulations for triangles.

3.	The Angle Criterion (degrees) defines the maximum angle between two neighboring elements; if this angle is reached, elements will be subdivided.

The element normal is checked versus the averaged normal at nodes as follows:

•	Element Normal is computed at the maximum level and normalized.

•	Averaged normal at nodes are computed:

•	Normal at nodes is normalized.

•	For each active element that is not at maximum level, the angle between its normal and the normal at its nodes is computed; and if this angle is greater than the defined criterion, the element is divided.

admesh_set

4.	If Thkerr > 0, a thickness error estimation is computed as follows:

Nodal thickness is computed as:

admesh_set_eq

where, A (Ek(n)) and t(Ek(n)) are the area and thickness of element Ek(n) containing node n.

Then the thickness error is evaluated for each element, E using the formula:

If the thickness error is greater than the criterion Thkerr, the element is divided.

5.	The Angle and thickness error criteria are only checked at frequency defined through “Time delay” format provided in /ADMESH/GLOBAL.

6.	Criteria Angle criterion and Thkerr can be used separately or combined.