Stress Diffusion Problems

WE now come to the case shown in fig. 14. This is intended to represent a simplification of a two‐spar wing, having an outer portion skin‐covered and an inner open portion, the two spars being built‐in at the inner end. The top and bottom skins will usually be reinforced with spanwise stiffeners and the application of torque to the box will induce end loads in these stiffeners, in addition to bending moments in the spars. These end loads are essentially a local effect, localized near the inner end of the skin‐covered portion of the wing, and at sections remote from the inner end the torsional stresses in the box will be given by the ordinary Batho formula.