Enter the Mesh module. Select Part from the Object field in the context bar, and select a part from the list.
From the main menu bar, select .
Abaqus/CAE displays prompts in the prompt area to guide you through the procedure.
Select one or more geometric entities—vertices, edges, faces, or entire regions—whose associativity you want to delete.
You can use a combination of drag select, ShiftClick, and CtrlClick to select geometric entities. For more information, see Selecting objects within the current viewport.
Note:
To delete the association of a native mesh region and create an orphan mesh, you must select the entire region.
If desired, you can toggle off Delete association from bounding entities in the prompt area.
By default, when you delete the associativity of a region, Abaqus/CAE also deletes the association between nodes, element edges, and faces and the corresponding vertices, edges, and faces.
When you have finished selecting geometric entities, click Done.
Abaqus/CAE highlights the geometric entities in red and the associated mesh entities in yellow so you can confirm your selections.
Click Yes to delete the mesh association or No to cancel your selections.
Repeat Steps 3 through 6 to delete the associativity of other areas, or click the cancel button 
in the prompt area to end the procedure.
tool in the Mesh module toolbox, or you can click the 
tool to display the Edit Mesh dialog box—the delete associativity method is located in the Mesh category within the dialog box. (For more information on the Mesh module toolbox, see Using the Mesh module toolbox.)