INELASTIC ANALYSIS OF SECTIONS SUBJECTED TO AXIAL FORCE AND BENDING MOMENT

This paper describes the development of a numerical model used for the inelastic analysis of sections subjected to combined axial force and bending moment. The objective of the model is to calculate the strain distribution across the section given the applied loads and the mechan ical properties of the material. The stress-strain relation is assumed to be bi-linear elastic-plastic in tension and compression. Exact sol utions for six modes of strain in pure elastic, pure plastic and elast ic-plastic in compression and tension are developed. A Newton-Raphson concept implemented in the iteration technique is used for determining the strain values epsilon(1) at the top and epsilon(2) at the bottom surfaces of the section. Although this analysis is for a rectangular s ection, this method is well suited to analyze members with more compli cated cross-sections, such as circular or triangular.