I did a finite element simulation on a Gable roof shell structure of 4 by 4 metres, of thickness 5 mm.

The maximum stress was at 4 x 10^8 MPa for von Mises stress. Is that too much?

Should I increase my thickness and rerun the simulation?

Edit:

The maximum stress was at 4 x 10^6 MPa for von Mises stress. Is that too much?

The elastic limit for Al 5052 is considered