How are loads distributed through a wing box structure?

Wing box load distribution involves: Aerodynamic lift creates bending moment (increases toward root), shear, and torsion; Upper skin carries compression (critical for buckling), lower skin carries tension (critical for fatigue); Spar caps carry primary bending loads as tension/compression couple; Spar webs and skins carry shear loads forming closed torsion box; Ribs transfer local loads and maintain shape; Stringers carry portion of bending and prevent skin buckling. Landing gear loads, engine loads, and fuel weight add discrete forces. Shear flow analysis determines skin/web stresses; idealized models (beam-rod) verify FEM for understanding. Internal fuel tanks create pressure loads on ribs.