Local axis tools

Special GiD commands related to local axis

• gid_groups_conds::local_axes_window

This Tcl procedure open a window to handle local axis assigned to entities

• correct_local_axes_with_lines nodes|elements <groupList> <groupLinesList>

To use this command must apply to some surfaces local axis automatic.

When generating the mesh each element will have a local axis with z' pointing to the surface normal at the element center, but the axes x' and y' will be arbitrary set parallels to a direction,

and maybe this automatic x' direction is not appropriated to be used for example to define the fibers direction of a composite material.

It is possible to select some auxiliary curves to generate an approximated interpolated field of directions,

nodes: to correct the current local axis on the nodes of the mesh

elements : to correct the current local axis on the elements of the surface's mesh

<groupList> a list of group names with the surfaces with applied local axis automatic that want to be enhanced in its mesh (nodes or elements)

<groupLinesList> a list of group names with the auxiliary curves

e.g.

Assuming a group named my_surfaces_group with some surface with automatic local axis applied, and a group named my_lines_group with some curves approximating the wanted local x' direction

set num_enhanced [correct_local_axes_with_lines elements [list my_surfaces_group] [list my_lines_group]]

The first image show a surface and a curve to be used to orientate the x' local axis, the second image show the automatic local axis, and the third image after call correct_local_axes_with_lines with the x' local axis 'near-parallel' to the auxiliary curve

Note: it is possible to call automatically this command when a mesh is generated, implementing GiD_Event_AfterMeshGeneration