You can position a datum point by selecting a point on the model and an line on which to project the point. ABAQUS/CAE creates the datum point where the selected plane intersects a line that is normal to it and passes through the selected point.
To create a datum point by projecting a point on a line:
From the main menu bar, select Tools
Datum.
The Create Datum dialog box appears. The dialog box outlines the types of datum geometry you can create.
ABAQUS/CAE displays prompts in the prompt area to guide you through the procedure.
Tip:
You can also create a datum point using the 
tool, located in the module toolbox. For a diagram of the datum tools in the toolbox, see “Using the Datum toolset,” Section 40.2.
From the list of types at the top of the dialog box, choose Point.
The Method list indicates the methods you can use to create a datum point.
From the Method list, select Project point on line and click OK.
From the part or assembly in the current viewport, select a point.
Select a straight line on which to project the point.
The datum point appears. You cannot modify a datum point created with this method; you must delete the old point and create a new one.
