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.