The structurally idealized, double symmetric flat panel in figure $4$ is subject to a bending moment M$.$ The panel contains a cut$-$out that is defined with respect to the same axes of symmetry as the flat panel. All the horizontal stiffeners in the panel have a boom area B$.$ The vertical stiffeners have boom area $2$B$.$

Answer the following questions:

The bending moment M causes normal forces in the horizontal stiffeners. Assume that the horizontal axis of symmetry coincides with the neutral axis.

a$.$ Sketch this undisturbed normal force distribution at the vertical edges of the panel. Note that he structure must be in equilibrium!

Now the cut$-$out is considered.

b$.$ Sketch the expected deformation of the cut$-$out caused by the applied bending moment M$,$ assuming that the cut$-$out has not been reinforced yet.

c$.$ Sketch the necessary disturbance load distribution in the cut$-$out that should cause the expected deformation.