As you can see, this is a shell and I want to load on the red line on the inside of the red circle, which is 3.6mm long and symmetrical about the midpoint of the upper edge.
You can apply load to individual element edges:
or (better) create a proper partition in CAD software before importing the geometry to PrePoMax.
I did it ,thanks for your reply.
I used umat for static analysis in the 2D plane above, and I found that stress1=S11, stress2=S22, but stress3 is not equal to S12, so where is stress S12 stored?
It should be the 4th component because the order is:
11,22,33,12,13,23