Effect of Uniaxial Eccentric Loading on Strength of Steel Built-Up Beam-Column Section
Authors :- Pipariya, M., Sharma, M.R.
Publication :- Recent Developments in Structural Engineering, Volume 3. SEC 2023. Lecture Notes in Civil Engineering, vol 548. Springer, 2025
Steel construction has a prominent place in field of construction industry. For heavy loads, the single sections or rolled sections found to be insufficient in their strength. It is mandatory to use of built-up section for high stresses. Under uniaxial bending with axial force, the section strength and member strength for single rolled sections and welded I and H sections may be determined by the interaction equations as per the codal provisions. It is found that currently used linear interaction equations generally lead to conservative result for built-up section in biaxial loading. Therefore, built-up sections are required to some modification in estimation for their load resisting capacity under combined uniaxial and biaxial forces. In this study, nonlinear sectional strength equations are derived for the design of back-to-back connected built-up channel section with connected flange plate under eccentric forces on both minor and major axis. The change in neutral axis location under eccentric uniaxial forces incorporates in this study resulting physical nonlinearity in section behavior. In this Paper, the variations in strength along the minor axis with variation in eccentric force along the major axis and vice versa are interpreted by interaction diagrams. Interaction curves for load-bending moment are developed for uniaxial bending.