You can select Tools
Virtual TopologyCombine Faces from the main menu bar to combine selected faces. During mesh generation, ABAQUS/CAE treats the combined faces as a single face and ignores any edges and vertices that were removed.
To combine faces:
From the Object field in the context bar, select a part or the assembly.
From the main menu bar, select ToolsVirtual TopologyCombine Faces.
Tip:
You can also combine faces using the 
tool, located in the Mesh module toolbox.
Select the faces that you want to combine.
You can use a combination of drag select, [Shift]+Click, [Ctrl]+Click, and the angle method to select more than one face to combine. For more information, see “Selecting objects within the current viewport,” Section 6.2.
Tip:
If you are unable to select the desired face, you can change the selection behavior by clicking the selection options tool 
in the prompt area. For more information, see “Using the selection options,” Section 6.3.
If the vertices at the end of any edges of the selected faces can also be ignored, ABAQUS/CAE highlights the vertices and asks if you want to include them in your selection. Click Yes to ignore the highlighted vertices. Click No to keep the highlighted vertices.
ABAQUS/CAE combines the selected faces and vertices. You can use the Model Tree to restore the selected faces and vertices by deleting or suppressing the Virtual Topology feature.