Creo Simulate > Modeling Structure and Thermal Problems > Features > Datum Curve > To Create a Datum Curve Using a Cross Section
  
To Create a Datum Curve Using a Cross Section
1. Click Refine Model > Datum and click the arrow next to Curve.
2. Click Curve from Cross Section. The Curve from Cross Section tab opens.
3. In the Cross section list, select the cross section to use to create the curve.
4. Click .
For more information, refer to the Part Modeling Help.