NUMERICAL STUDY OF STRUCTURAL STEEL CONTINUOUS BEAMS WITH TUBULAR CROSS-SECTIONS
Xiang Yun 1* and Leroy Gardner 1
1 Department of Civil and Environmental Engineering, Imperial College London, UK
The structural behaviour and design of hot-rolled and cold-formed steel continuous beams with square and rectangular hollow sections are studied in this paper, with a focus on the beneficial effects of material strain hardening and moment redistribution. Finite element (FE) models were first developed and validated against existing test results, upon which parametric studies were carried out to expand the available structural performance data over a range of cross-section geometries, cross-section slendernesses, steel grades and loading conditions. The experimental results, together with the parametric numerical results, were then used to evaluate the accuracy of the design provisions of EN 1993-1-1 as well as the continuous strength method (CSM) for indeterminate structures, the latter of which is extended in scope in the present study. It was shown that the current provisions of EN 1993-1-1 for the design of continuous beams are rather conservative, while the proposed CSM yields a higher level of accuracy and consistency, due to its rational consideration of both strain hardening at the cross-sectional level and moment redistribution at the global system level.
Cold-formed tubular sections; Continuous beams; Continuous strength method; Hot-rolled tubular sections; Numerical modelling; Plastic design