INTEGRATED ANALYSIS OF LOADING ECCENTRICITY ON RESPONSE OF A COLUMN UNDER TRAVELLING FIRE

Columns are crucial structural elements designed to carry axial loads. When these loads are applied off the column's central axis, it results in eccentric loading, introducing both axial stress and bending moments in the column. This complexity becomes even more pronounced under transient heating conditions, such as those encountered during travelling fires. Understanding these interactions is vital for designing structures that can withstand unusual loading and heating scenarios, ensuring their safety and resilience. In consideration of this, the present study undertakes nonlinear analyses to explore the effects of eccentricities due to load positioning and also the effects of transient heating on columns and beams exposed to traveling fires. The analysis is conducted in two phases: initially, an isolated steel column is subjected to full-scale traveling fires, considering axial loading with eccentricity ratios (e/h) of 0, 0.25, and 0.5. Subsequently, a two-bay frame is exposed to the combined effects of traveling fires and imposed loads. The computational modelling for this investigation is done using Abaqus software. Findings from the analysis reveal that increased eccentricity significantly enhances lateral deformation and triggers local buckling in flanges. Columns under higher eccentricity also display lower temperatures at which buckling occurs. Additionally, for steel frames, the combination of transient heating and imposed loads brings about both axial and flexural deformations in structural members. As eccentricity escalates, there's a notable reduction in critical load, precipitating premature section failure and significant lateral displacement. Furthermore, critical stresses are observed at beam-column junctions, and a twisting phenomenon occurs when beams are subjected to transient heating while columns remain at ambient temperatures.