When you define a mesh with Automatic Mesh Sizing, you define a process that the Mesher uses to generate the mesh. Unlike materials and boundary conditions, a mesh definition is a set of commands issued in a specific order. When you change the order of these commands, you often change the resultant mesh.
The Mesh Size branch of the Design Study bar lists every step in the mesh definition history. This includes when Automatic Sizing is invoked, size adjustments, and when Spread Changes is applied. Each step is listed as a separate branch, and can be modified, disabled, or deleted from the mesh definition.
All steps in the history constitute the mesh definition. Certain mesh definition commands prompt question dialogs regarding the re-institution of existing adjustment settings or the removal of existing mesh sizes. The responses to these questions affect the current mesh definition, but they do not remove earlier steps in the history. New steps are added to the definition may change the distribution and may even "undo" the effects of earlier steps.
These are the primary benefits of the Mesh History:
Global settings such as Surface refinement, Gap refinement, and the Length scale appear under the Model mesh settings branch.
All other steps in the mesh definition are listed in the order they are applied to the model.
To change an existing setting in the mesh distribution:
Most mesh distributions on complex models are defined through a series of commands and refinements. Because every setting is accessible in the History, it is easy to modify a specific setting in the mesh definition.
To rebuild the mesh distribution:
When a setting is modified or deleted, a "warning" icon is displayed over the Mesh Size branch:
This means that the mesh distribution is out of date and needs to be rebuilt.
To disable a setting:
Sometimes it is useful to temporarily remove a setting without deleting it. This can be help determine the effect a setting has on the mesh distribution.
To modify an existing mesh refinement region: