Surface traction Unit

[paulo44]

Hi,

I am currently making a composite calculation, based on a shell model.
I first applies a surface traction as load

The force is applied on the surface is 480N et the surface is 300 mm².
I applied so a 480/300=1.6 Mpa force when I defined the load.

Then,I tried the same calculation but with 4 applied forces on 4 different points of the surface.On each node, I applied a 480/4=120N force.

The result shoul be approximately the same in the two cases, but the second method provides Stress and displacement twice more important than with the first one.

Where do I made a mistake?

Thanks!