Is it an orientation issue: Same load but different sens???

[Mohamed Zied]

I tried to applied load on the top surface of the girder which is composed of 7 parts. But, as you can see in the attached screenshot, the load appears in the opposite direction in the edge and middle parts.
is there any explanation of that? is it about parts' orientation?
I tried to apply the global orientation to parts but it didn't work. Moreover, when I applied load with a minus sign to edge and middle parts, results were abnormal, especially for displacement and stresses.

 

[FEA way]

Is that a shell part ? Which type of load did you use ? Please attach a picture showing the top surface of this part.

 

[Mohamed Zied]

Thank you for your quick reply.
Yes, it is an assembly of shell parts. The used load is pressure (to simulate a distributed load of the deck on the steel girders).
The attached screenshot is a zoom of the top surface and it covers parts 1 and 2.

 

[FEA way]

When you apply pressure load to shell surface you have to choose a side (brown or purple). Make sure that it’s correct for all parts of the top surface. You may also have to flip shell normal (in Property module use Assign —> Element Normal).