Axial-moment interaction and load path dependency for steel columns (2017)
Type of ContentConference Contributions - Published
AuthorsCollow, A., Chand, A., Lu, Y. C., Lee, C.-L., MacRae, G.show all
This paper discusses the effect of out-of-straightness direction, major-minor moment interaction and path dependency for steel columns. This has been undertaken by using the Extended Direct Analysis (EDA) method which has been developed for analysing a simple low-rise 3D steel frame structure under 3D biaxial loadings in arbitrary load-paths from first principles. It takes into account non-ideal conditions, residual stresses, member out-of-straightness, statistical variation in capacities, plasticity, and second-order geometric effects. It was found steel columns are path dependant, with the plastic capacity reducing by up to 18% when the loading occurs in the major and minor axis at the same time. By completing bi-directional loading on a simple 3D frame it was found that the maximum critical load on the major and minor axes reduced by 10% when compared to the 2D EDA method which does not consider major-minor moment interaction. Therefore it is concluded that the tangent modulus is a function of axial load, moment and load path. Further research is required to account for torsional effects and shear before this method can be used for design.
ANZSRC Fields of Research09 - Engineering::0905 - Civil Engineering::090506 - Structural Engineering
09 - Engineering::0905 - Civil Engineering::090502 - Construction Engineering