Stresses in the swept-back box-beam subjected to the transverse load are analysed in the method similar to that of the author's foregoing paper, in which the muti-bayed unswept boxbeam is easily analysed by considering the deviation stress from that of engineering beam theory. In the swept-back box-beam, it is found at first that the engineering beam theory must be modified, and stresses are divided into stresses of modified engineering beam theory and of deviation. The deviation stress equations for swept-back box-beam are derived and whole equations are easily solved by successive approximation as the unswept box.
Due to the fact that the first approximation of these deviation stress equations approximates well to the rigorous solution, it is clear also in the swept-back box-beam that the design of the optimun size of structural componets is directly evaluated in satisfactory accuracy by considering the first approximation.
Effect of the carry-through is similarly treated.