Determination of the stress distribution in reinforced monocoque structures Part 1 A theory of flat-sided structures

Abstract

This paper is concerned with the formation of basic differential equations for the determination of the stress distribution in reinforced monocoque flat-sided structures, such as rectangular or polygonal fuselages and wing boxes. The general scheme of the analysis is to develop the fundamental equations which govern the stresses, strains and displacements separately in the skin-stringer combination and rib flanges. Then, by identifying displacements along their intersections, the differential equations of compatibility are formed. The solution of these equations yields the stress distribution. It is intended that further papers will be devoted to the detailed solution and application of these equations to particular problems together with experimental verification for each type of problem. A simple application of the theory is demonstrated in an appendix. A three-bay flat structure, containing a rectangular cut-out in the centre bay, under uniformly distributed tension loading is investigated. The calculated results for the longitudinal direct stress resultants in the skin-stringer combination compare favourably with those of experiment.