*coarsening_mesh

Performs mesh coarsening on selected components.

Syntax

*coarsening_mesh comps_mark_id nodes_mark_id failed_comps_mark_id elem_size elem_type feature_angle max_diameter update_rigids reserved2 create_plotels

Type

HyperMesh Tcl Modify

Description

Performs mesh coarsening on selected components. The ability exists to specify sacred nodes that will be maintained after coarsening.

Inputs

comps_mark_id

The ID of the mark containing the input components. This must also include any 1D multi-leg rigid elements that will be processed by the update_rigids option. Valid values are 1 and 2..

nodes_mark_id

The ID of the mark containing any nodes to be treated as sacred/fixed. These nodes must belong to the initial mesh. These nodes will be maintained during coarsening. Valid values are 1 and 2.

failed_comps_mark_id

The ID of the mark to store any failed components. Valid values are 1 and 2.

This mark can then be passed to *decimate_mesh for further processing.

elem_size

The element size to use for coarsening. This must be larger than the initial mesh size.

elem_type

Flag indicating the element type to generate for the coarsened mesh. Valid values are:

0 – trias
1 – quads
2 – mixed
3 – right trias
4 – quads only

feature_angle

This specifies the maximum angle between the normals of two connected elements. This value is ignored for shell elements. For 3D elements, the appropriate free faces of shell elements are created and meshed with the given feature angle. This value is also used to construct the connected edges for the failed components. Then these components are coarsened/decimated in a second attempt.

If this value is less than 1.0, the default value of 85.0 degrees is used.

max_diameter

This option specifies the maximum hole diameter that will be filled by the coarsening operation. The default value is 0.0 (do not fill any holes).

options

Flags that specify various methods of pre-processing and post-processing of 1D and 2D elements. Bit values are used and the value is calculated as (Bit0 + 2*Bit1 + 4*Bit2 + 8*Bit3 + 16*Bit4 + 32*Bit5 + 64*Bit6).

Bit0: 0 – Do not utilize this option.; 1 – All selected 1D element paths not sharing sacred nodes must be deleted before mesh coarsening. 1D elements paths comprising sacred nodes are preserved. Unselected 1D elements are ignored. Preserved 1D elements which are not free should be attached to the shell mesh after coarsening..

Bit1: 0 – Do not utilize this option.; 1 – Selected 1D elements that appear free (are not attached to the shell or solid mesh) after mesh coarsening must be deleted after meshing. 1D elements sharing sacred nodes must be preserved.

Bit2: 0 – Do not utilize this option.; 1 – Selected 1D multi-leg elements having free legs after meshing (are not attached to shell or solid mesh) must be updated by deleting the free legs.

Bit3: 0 – Do not utilize this option.; 1 – Selected 1D elements remaining after meshing should be converted to plot elements.

Bit4: 0 – Do not utilize this option.; 1 – Selected 2D elements should be converted to plot elements after meshing. This flag is utilized only for the OptiStruct user profile.

Bit5: 0 – Do not utilize this option.; 1 – Retain the input mesh, and organize the coarsened mesh into a new component.

Bit6: 0 – Do not utilize this option.; 1 – Creates 1D plotel elements on coarsened 2D element edges.

Examples

Create a coarsened mesh with mixed type elements of element size 30 using all components. Put failed components on mark ID 2. Keep node IDs 16 and 27 as anchor nodes. Ignore all internal loops with diameter less than 65. If the model has solid elements, create free faces of shell elements and mesh them with a feature angle of 45 degrees. Delete selected 1D elements not sharing sacred nodes before meshing (option Bit0=1). Delete selected free 1D elements after meshing (option Bit1=1). If the model has rigidlink/RBE3 elements, delete any free legs in the input components (option Bit2=1). Convert 1D elements to plot elements after meshing (option Bit3=1). The options are computed as 1 + 2 + 4 + 8 = 15:

*createmark components 1 "all"
*createmark nodes 1 16 27
*coarsening_mesh 1 1 2 30.0 2 45.0 65.0 15

Errors

Incorrect usage results in a Tcl error. To detect errors, you can use the catch command:

if { [ catch {command_name...} ] } {
   # Handle error
}

Version History

11.0

2019 – Corrected documented argument list to remove invalid reserved1, update_rigids, reserved2 and create_plotels arguments, and add correct options argument and description. Added new options values for Bit5 and Bit6.