Approximate Solutions for Struts Supported by an Elastic Foundation: Demonstrations, for Certain Typical Stress Conditions, of the Application of the Energy Method Available to Purchase

THE case of a strut supported by a number of elastic supports is one that frequently occurs, in structural analysis; an obvious example from monocoque fuselages is that of the longeron loaded in compression and supported at intervals by frames which deform elastically under lateral load from the longeron. From a stressing point of view, the criterion for strut strength is not usually the critical buckling load but the load required to give maximum allowable stress under conditions of initial end eccentricity or initial free deflexion of one or more of the supports. In the case of a simple unsupported strut, for instance, it is the application of eccentrically applied end load that provides the strength criterion, and not the critical buckling under axial end load. Although the determination of the critical buckling load is interesting from an analytical point of view, and is also useful as a standard of reference, solutions of the ‘stress’ conditions have more practical significance for the stress engineer.