ABSTRACT
ABSTRACT: The Ramberg-Osgood law provides the most accurate description of the stress/strain relationship of aluminium alloys (and many other materials). Repeated numerical integration of this function will result in a database for the acting bending moment and the relative rotation in a rectangular cross-section. Using this base an approximating moment-curvature function can be established in a modified form of the Ramberg-Osgood law. Approximating values of the moment, which causes conventional yield stress or ultimate stress in the extreme fibre, can be stated also. Changing the strain in the extreme fibres and numerically integrated the stress function one can get relating data for the actual normal force, bending moment, strain and relative rotation. Analysing these data we have found relations for the normal force -bending moment pairs, which results yield or ultimate stress in the most loaded extreme fibre. Function for the moment-relative rotation curvature in case of simultaneous normal force also sated. Published values and relations will be applicable in further research.
