Group of meshes

If the same meshes are used for all the analyses, the following section can be skipped.

A new concept has been introduced in Postprocess: Group, which allows the postprocessing of problems which require re-meshing or adaptive meshes, where the mesh change depending on the time step.

Normal operations, such as animation, displaying results and cuts, can be done over these meshes, and they will be actualized when the selected analysis/step is changed, for example by means of View results -> Default analysis/step

There are two ways to enter in GiD the diferent meshes defined por diferent steps or analysis:

1. define separate files for each mesh, for instance:

• binary format: mesh+result_1.post.bin, mesh+result_2.post.bin, mesh+result_3.post.bin, ...

• ascii format: mesh_1.post.msh + mesh_1.post.res, mesh_2.post.msh + mesh_2.post.res, ...

Note: the steps values ( or analysis) should be diferent for each pair mesh+result.

To read them you can use File-->Open Multiple (see POSTPROCESS > Files menu from Reference Manual)

2. define on binary file or two ascii files (msh+res):
Meshes that belong to a group should be defined between the following highlighted commands
Group "group name"
MESH "mesh_name" dimension ...
...
end elements
MESH "another_mesh" ...
...
end elements
end group

Results which refer to one of the groups should be written between these highlighted commands

OnGroup "group name"
Result "result name"
...
end values
...
end ongroup

Note: GiD versions 7.7.3b and later only allow one group at a time, i.e. only one group can be defined across several steps of the analysis. Care should be taken so that groups do not overlap inside the same step/analysis.

For instance, an analysis which is 10 steps long:

For steps 1, 2, 3 and 4: an 'environment' mesh of 10000 elements and a 'body' mesh of 10000 elements are used

MESH "environment"
... Coordinates
...
10000 ...
end elements
MESH "body" ...
...
20000 ...
end elements

and its results

GiD Post Results File 1.0
...
Results "result 1" "time" 1.0 ...
...
Results "result 1" "time" 2.0 ...
...
Results "result 1" "time" 3.0 ...
...
Results "result 1" "time" 4.0 ...
...
end values

For steps 5, 6, 7 and 8: with some refinement, the 'environment' mesh now being used has 15000 elements and the 'body' mesh needs 20000 elements

MESH "environment"
...
Coordinates
...
15000 ...
end elements
MESH "body" ...
...
35000 ...
end elements

and its results are

GiD Post Results File 1.0
...
Results "result 1" "time" 5.0 ...
...
Results "result 1" "time" 6.0 ...
...
Results "result 1" "time" 7.0 ...
...
Results "result 1" "time" 8.0 ...
...
end values

For steps 9 and 10: the last meshes to be used are of 20000 and 40000 elements, respectively

MESH "environment" ...
Coordinates
...
20000 ...
end elements
MESH "body" ...
...
60000 ...
end elements

and its results are

GiD Post Results File 1.0
...
Results "result 1" "time" 9.0 ...
...
Results "result 1" "time" 10.0 ...
...
end values

There are two ways to postprocess this:

• store the information in three pairs (or three binary files), thus:
  • steps_1_2_3_4.post.msh and steps_1_2_3_4.post.msh (or steps_1_2_3_4.post.bin)
  • steps_5_6_7_8.post.msh and steps_5_6_7_8.post.msh (or steps_5_6_7_8.post.bin)
  • steps_9_10.post.msh and steps_9_10.post.msh (or steps_9_10.post.bin)

and use the 'Open multiple' option (see POSTPROCESS > Files menu from Reference Manual) to selected the six (or three) files; or

• write them in only two files (one in binary) by using the Group concept:

all_analysis.post.msh (note the group - end group pairs)

Group "steps 1, 2, 3 and 4"
MESH "environment" ...
...
MESH "body" ...
...
end group
Group "steps 5, 6, 7 and 8"
MESH "environment" ...
...
MESH "body" ...
...
end group
Group "steps 9 and 10"
MESH "environment" ...
...
MESH "body" ...
...
end group

and

all_analysis.post.res (note the ongroup - end ongroup pairs)

GiD Post Results File 1.0
OnGroup "steps 1, 2, 3 and 4"
...
Results "result 1" "time" 1.0 ...
...
Results "result 1" "time" 2.0 ...
...
Results "result 1" "time" 3.0 ...
...
Results "result 1" "time" 4.0 ...
...
end ongroup
OnGroup "steps 5, 6, 7 and 8"
...
Results "result 1" "time" 5.0 ...
...
Results "result 1" "time" 6.0 ...
...
Results "result 1" "time" 7.0 ...
...
Results "result 1" "time" 8.0 ...
...
end ongroup
OnGroup "steps 9 and 10"
...
Results "result 1" "time" 9.0 ...
...
Results "result 1" "time" 10.0 ...
...
end ongroup

and use the normal Open option.