*slivertetrafix

Fixes sliver tetra and wedge elements and optimizes node positions based on certain quality criteria.

Syntax

*slivertetrafix mark_id options

Type

HyperMesh Tcl Modify

Description

This command is used to fix sliver tetra and wedge elements and performs node position optimization of poor elements using quality criteria measurements.

Inputs

mark_id
The ID of the mark containing the tetra elements to fix. Valid values are 1 and 2.
options
This parameter constructs a table of values that comprise both the methods that should be used to fix the sliver elements, along with quality criteria that are used optimize poor element nodes. Valid fixing methods include:
fix_sliver
  • 0 – Do not fix sliver tetras.
  • 1 – Fix sliver tetras.
fix_wedge
  • 0 – Do not fix wedge tetras.
  • 1 – Fix only the internal edge of wedge tetras.
  • > 1 – Fix both internal and boundary edges of wedge tetras.
optimize_node
  • 0 – Poor element nodes will not be optimized.
  • 1 – Optimize only internal nodes of poor elements.
  • > 1 – Optimize both internal and boundary nodes of poor elements.

The user can neglect one or more of the above options and the command will use the default values (fix_sliver 1, fix_wedge 1, optimize_node 0).

The following quality measurements are available for fixing nodes when optimize_node is ≥ 1. Each measurement includes the measurement name, failed value, warn value, good value, weight, and solver ID (currently only HyperMesh solver ID = 0 is supported). Valid quality measurements include:

aspect_ratio

tet_collapse

vol_skew

skew

vol_ar

warpage

min_interior_angle

max_interior_angle

jacobian

For every item, you can chose to only input the name and some values; in this case, the remainder will use the default values.

Examples

To fix sliver and internal wedge tetras of displayed elements:

*createmark elems 1 displayed
set table ""
*slivertetrafix 1 $table

Fix the displayed poor elements and optimize the internal nodes by using the tet_collapse and vol_skew quality measurements. Only the element’s whose tet_collapse is < 0.01 and vol_skew is > 0.9 will be optimized. The weight of vol_skew is 2. All others values are used as the default:

 *createmark elems 1 displayed
set table "optimize_node 1 tet_collapse 0.01 vol_skew 0.90 0.60 0.10 2"
*slivertetrafix 1 $table

Errors

Invalid or inconsistent input parameters in *slivertetrafix result in a Tcl error. To detect errors, you can use the catch command:

if { [ catch {* slivertetrafix 3 $table} ] } {
# Handle error
}

Version History

10.0