While conducting a structural analysis FEA for an aircraft wing, I had to import the CFD pressures acting on the wing, lets say at an A.o.A = 10 deg, at 80 m/s and at sea level, and say the atmospheric pressure is 1 atm. Should the imported pressures from CFD analysis (on the top surface and bottom surface of the wing) be the absolute static pressures or the net pressures? (Assuming the wing surfaces have no slip condition).
If I use the absolute pressures, then the top surface would be experiencing a positive pressure meaning that the pressure is acting onto the top surface (causing it to shrink), and if I use net pressure then that would be negative meaning that the pressure is acting out of the top surface (causing it to expand).
Which one is true? I think that absolute pressures should be used because if, for example, we want to know the structural behavior of the wing top/bottom surface under 1 atm only (assuming wing is symmetric and at an A.o.A = 0 deg), then the net pressures would be zero and we wouldn't have any forces acting on the top or bottom surface of the wing.
Also, does the wing's top surface, in reality when it is flying, deform out (i.e. expands) or deforms in (i.e. shrink)? I think since the absolute pressure is still positive so it must deform in, but some sources say that it instead deforms out. (Assume a static structural condition). A such source I am attaching in the picture.