Column Buckling in the Elastoplastic Range

A theory of inelastic buckling of a column of constant, Hshaped section is presented and an approximate procedure of solution indicated. The numerical application confirms qualitatively the results found by Shanley on the idealized semirigid strut. On this last simplified scheme the effect of initial eccentricities is investigated and Southwell's plot analyzed. Considering the curvature of the stress-strain characteristic, it appears that , in accordance with experimental observations, the load decreases with increasing deflections after reaching a value that , for small initial eccentricities, may not attain the tangentmodulus value.