Behaviour of high strength steel columns under fire conditions

Structural fire design of SHS, RHS and CHS high strength steel columns

“…The third phase involves a strength plateau between e y,u and a strain of 15% (specified as e t,u ) and finally, the stress declines to 0 at an ultimate strain (e u,u ) value of 20%. This procedure has been shown to sometimes overestimate the stress at certain levels of elevated temperature for some grades of HSS (Winful et al, 2018). One shortcoming of this method is that the stress-strain response for some high strength steels can be overestimated in the region between the proportional limit ( f p,u ) and yield point ( f y,u ), which may result in an overestimation of the buckling capacity of an HSS element in a fire scenario.…”

“…At elevated temperature, some researchers choose to employ the modified Ramberg-Osgood (Gardner and Nethercot, 2004;Winful et al, 2018) material model to represent the steel material response, which is an extension of the initial form (Ramberg and Osgood, 1943) revised by Hill (1944) for isothermal conditions. The advantages of this approach, compared with the Eurocode method, has been demonstrated (Knobloch et al, 2013;Pauli et al, 2012).…”

“…The HSS material properties at elevated temperature reported by Winful et al (2018) are used in this study, which are provided in Table 5 and 6 for S690QL and S700MC, respectively. The two-stage modified Ramberg-Osgood material model provided in equations (1) and ( 2) is employed to idealise the full-range stress-strain response for HSS at elevated temperatures.…”

“…In recent years, there have been significant improvements to available design guidance for HSS structures, as well as a greater emphasis given to the sustainability of a structure. These have developed from a series of research programmes including collaborative European projects (HILONG Final Report, 2017;RUOSTE Final Report, 2016), analysis of beams and columns (Varol and Cashell, 2017;Wang et al, 2016;Winful et al, 2018) and also studies into various loading scenarios (Hu et al, 2017;Javidan et al, 2017). As a consequence, there is generally wider product availability and the use of high strength steel (HSS) in structural applications in growing.…”

Behaviour and design of eccentrically loaded hot-rolled steel SHS and RHS stub columns at elevated temperatures

“…Extensive experimental and numerical research has been carried out into the fire behaviour and resistance of steel structural components, including stub columns [13][14][15][16], columns [17][18][19][20][21][22][23], beams [24][25][26] and beam columns [27][28][29][30]. However, the fire performance of hot-rolled steel square and rectangular hollow sections (SHS and RHS) under combined compression and bending has received relatively little attention.…”