Select Mesh
Edit from the main menu bar to adjust the position of midside nodes of second-order elements.
You can use this tool to allow for the singularity at the crack tip in a fracture mechanics analysis. However, this tool will allow you to edit any second-order elements; it does not check that you are editing the degenerate quadrilateral or wedge elements required by a fracture mechanics analysis. For more information, see “Controlling the singularity at the crack tip for a small-strain analysis,” Section 20.1.5, and “Constructing a fracture mechanics mesh for small-strain analysis” in “Contour integral evaluation,” Section 11.4.2 of the ABAQUS Analysis User's Manual.
You can select nodes and enter a bias parameter between 0 and 1. ABAQUS/CAE moves the midside nodes along connected element edges to a position based on the parameter that you entered. For example, if you enter a parameter of 0.25, ABAQUS/CAE biases the position of the midside nodes one quarter of the length of the element edge away from the selected nodes.
To adjust the position of midside nodes:
Enter the Mesh module.
From the Object field in the context bar, select Part and select an orphan mesh part from the list of parts. This tool is available only for working on an orphan mesh part.
From the main menu bar, select MeshEdit.
ABAQUS/CAE displays the Edit Mesh dialog box.
Tip:
You can also display the Edit Mesh dialog box using the 
tool, located at the bottom of the Mesh module toolbox.
In the dialog box, do the following:
In the Category field, select Node.
From the Method list, select Adjust midside.
Click OK.
ABAQUS/CAE displays the existing nodes. In hidden and shaded mode, only the visible nodes are displayed.
Select the nodes toward which the position of midside nodes along connected element edges will be adjusted. You can select nodes, or you can select element edges. If you select element edges, ABAQUS/CAE selects the nodes along the element edges.
You can [Shift]+Click on individual nodes to add them to your selection, or [Ctrl]+Click on selected nodes to remove them from your selection.
Tip:
You can change the picking behavior by clicking the selection options tool 
in the prompt area. For more information, see Chapter 6, “Selecting objects within the viewport.”
If you would rather select from a list of existing node sets, do the following:
Click Sets on the right side of the prompt area.
ABAQUS/CAE displays the Region Selection dialog box containing a list of node sets that you have created.
Select the set of nodes, and click Continue.
Note: The default selection method is based on the selection method you most recently employed. To revert to the other method, click Select in Viewport or Sets on the right side of the prompt area.
In the prompt area, enter the value of the bias parameter. You must enter a value between 0 and 1.
ABAQUS/CAE moves the midside nodes along connected element edges to the specified position.
Tip: If you make a mistake while adjusting nodes, click Undo in the Edit Mesh dialog box to undo the adjustment. ABAQUS/CAE restores the nodes to their previous positions.
Repeat Steps 4 and 5 as often as necessary to adjust additional midside nodes.
When you have finished adjusting nodes, click the cancel button 
in the prompt area to exit the procedure.
