Abstract
Deformation of cross-section of H-beam under unsymmetrical bending is analysed theoretically. The analysis is carried out by use of so called energy principle, on the assumption that the displacement at any point on the cross-section of H-beam under unsymmetrical bending includes undefined coefficients. These coefficients are determined so as to minimize the functional given by the product of stress and strain. Theoretical results coincide well with the fact that sagging deformation of inner or compression side flange is larger than that of outer or tension side flange. It is also found that the lager the strain hardening exponent, n, the larger the sagging deformation of flange and web.
