**build_ellipse

Description

This command builds the surface mesh of an ellipse using s3d3 elements.

Synatx

**build_ellipse [ *name name ] \(~\,\) *center (center) \(~\,\) *normal (normal) \(~\,\) *dir (direction) \(~\,\) *ra ra [ *rb rb ] \(~\,\) *nb_nodes nb_nodes

*name

the name of the elset; by default “ellipse”

*center

the center of the ellipse; by default center = (0,0,0)

*normal

the normal to the ellipse plane; by default normal = (0,0,1)

*dir

the direction of the ellipse; by default dir = (1,0,0)

*ra

the radius in dir-axis

*rb

the radius in the normal to dir-axis. If not given, the value of rb is set to be equal to ra.

*nb_nodes

the number of nodes to build the ellipse. Default value nb_nodes = 16.

Example

***mesh
 **build_ellipse
  *center ( 0.00000 0.00000 0.00000 )
  *normal ( 0.00000 1.00000 1.00000 )
  *dir ( 1.00000 0.00000 0.00000 )
  *ra 2.00000
  *rb 4.00000
  *nb_nodes 10

This example creates a mesh of an ellipse surface in 3D.

**mesh_quarter_disk

Description

This command creates the mesh of the quarter of an elliptic disk using quadrilateral elements.

Syntax

**mesh_quarter_disk \(~\,\) [ *radius radius] \(~\,\) [ *ncut_radius cut_rad] \(~\,\) [ *ncut_theta cut_theta ] \(~\,\) [ *ncut_height cut_y ] \(~\,\) [ *start_at start || *anisotropy aniso ] \(~\,\) [ *use_triangles] \(~\,\) [ *quad]

radius

The radius of the disk.

ncut_radius

the number of subdivisions along the radius.

ncut_theta

the number of subdivisions along theta.

ncut_height

for elliptic disks, the number of subdivisions in the y-direction. By default, ncut_y = ncut_rad.

start_at

consider only the section of the quarter disk having \(y\geq start\). It creates an anisotropic mesh but not elliptical.

anisotropy

to build an elliptic disk (with radius*aniso and radius are the values of semi-major/minor axes). For a circular disk, \(aniso = 1\).

quad

a flag to set quadratic interpolation.

use_triangles

a flag to use triangular elements to mesh the disk (By default c2d4/c2d8 are used). By setting this option, this mesher becomes similar to **build_ellipse.

Example

****mesher
 ***mesh disk.geof
  **mesh_quarter_disk
   *ncut_radius 12
   *ncut_theta 16
   *ncut_height 8  % or 12 for the circular disk
   *anisotropy 1.5 % or 1. for the circular disk
****return