For a summer job I am employed to look into the use of composite paneling in place of sheet aluminum with stiffeners. I am suppose to find the required thickness of composite wall paneling in order to make a structure such as the one attached. Obviously it will depending on the material properties of the panel, however assuming I know those, do you have any ideas on how I would go about this. I would be designing for a distributed load of 200 psf. I could do this if it was a uniformly distributed load or point load and a beam, but I am having trouble modeling this structure. For example I have no clue what this objects moment of inertia is, which is required. Any ideas?