Hi thanhttdt,

I checked the ANSYS Help file and the entry for Force under the category of Topology, Nodes are supported, while the entry for Pressure under the category of Topology, there is no mention of element faces (I didn't expect nodes since pressure needs an area). I should put this in as an enhancement request, since you have a good example of why it would be useful.

I'm curious why, when I had a worksheet that selected nodes, I couldn't apply a force either, just like you saw for pressure. This should work and I hope someone can explain why it's not working.

If this was to work, you could convert the pressure to force since you are selecting an area.

I have attached the ANSYS 18.2 archive.