Abaqus/CAE assigns a default top-down meshing technique to each meshable region of your model based on the geometry of the region and the current element shape selection for that region. Abaqus/CAE uses the mesh technique assigned to a region to generate a mesh for the region. You can use the Mesh Controls dialog box to select an alternate meshing technique.
To select a meshing technique:
From the main menu bar, select Mesh
Controls.
Abaqus/CAE displays prompts in the prompt area to guide you through the procedure.
Tip:
You can also set the meshing technique using the 
tool, located in the Mesh module toolbox.
If your part or assembly contains more than one region, select those regions whose meshing technique you want to view or modify and press mouse button 2. The selected regions must all have the same dimensionality.
The Mesh Controls dialog box appears.
From the list of Technique options, select the meshing technique of your choice. (Some techniques are available only if they are valid for the selected region.)
Abaqus/CAE selects As is if, in the previous step, you selected multiple regions that have different meshing techniques already assigned to them.
Select Free to create a free mesh.
Select Structured to create a structured mesh.
Select Sweep to create a swept mesh.
Select Bottom-up to create a bottom-up mesh.
Abaqus/CAE selects Multiple if a change in element shape assignment results in multiple techniques being assigned automatically to the selected regions. For example, suppose the free meshing technique is applied to all the regions of a solid part instance. If you change the element shape assignment of these regions from Tet to Hex or Hex-dominated, Abaqus/CAE automatically changes the meshing technique assigned to each region from the free meshing technique to whatever technique is appropriate for each region; for example, structured meshing for some regions and swept meshing for others.
Note: The bottom-up meshing technique must be manually assigned to or removed from a region. When you modify the geometry of a region to which the bottom-up meshing technique is assigned, the resulting region or regions will also be assigned the bottom-up meshing technique. You can click Defaults in the Mesh Controls dialog box to assign a top-down technique to a bottom-up region.
Click OK to close the dialog box and to save your mesh technique selection.
The next time you generate a mesh on the selected part instance or region, your selections will be honored.
If the selected region already contains a mesh, you will be prompted to delete the mesh or to cancel the mesh control procedure.
