There is no load applied to the blank when I used *LOAD_MASK. What might be the problem?

When I used *LOAD_MASK for hydro-forming analysis, first I have no problem in applying the load, but the load is in the wrong direction. I used negative value for the load curve to reverse the load direction. However, there was no load applied to the blank anymore. What might be the problem?

If *LOAD_MASK is used, when defining the load curve, only positive value can be used, and negative value will be ignored.

If you want to change the direction of the applied pressure, reverse the blank normals (this is the only way). (When using *LOAD_SEGMENT, you can use negative load)