Stability and design of normal and high strength steel CHS beam-columns

Experimental and numerical investigation of S700 high strength steel CHS beam–columns after exposure to fire

“…which has been extensively employed for modelling high strength steel tubular sections [25,26,36,37,43,44], was used herein. On the basis of a prior mesh sensitivity study considering mesh sizes from 0.01D × 0.01D to 0.1D × 0.1D, the final mesh size was selected as 0.05D × 0.05D, which led to a good balance between computational accuracy and efficiency.…”

“…Initial global and local geometric imperfections were incorporated into each modelled S700 high strength steel CHS beam-column, with the respective distribution profiles assumed to be the lowest elastic global and local buckling mode shapes, as derived from eigenvalue buckling analyses [25,26,36,37,43]. Three global imperfection magnitudes, including the measured value ωg and two generalised values, Le/1000 and Le/1500, in combination with two local imperfection magnitudes, both generalised values, t/10 and t/100, were used to factor the corresponding distribution profiles; this led to a total of six combinations of global and local imperfection magnitudes being examined.…”

“…Wang and Liu [23] and Li et al [24] conducted experimental and numerical investigations into the flexural buckling behaviour of high strength steel box and Isection columns after exposure to fire and proposed design methods to predict their residual compression capacities. Complementing the existing research on the fire and post-fire performance of high strength steel structures, as well as the studies into the room temperature response of high strength steel circular hollow section (CHS) beam-columns [25,26], the present study focuses on the global buckling behaviour of S700 high strength steel CHS beamcolumns after exposure to fire.…”

Buckling resistance of hot‐finished CHS beam‐columns using FE modelling and machine learning

“…The coldformed CHS exhibit a continuous rounded stress-strain response caused by cold-working throughout the forming process, whereas the hot-finished CHS have a linear elastic response followed by well-defined yield plateau and moderate degree of strain hardening [16][17][18][19][20][21]. More recently, Meng and Gardner [22] conducted a series of experimental and numerical tests on hot-finished and cold-formed CHS beam-columns made from both normal-and high-strength steels. Further experimental and numerical research work on CHS beam-columns is still considered necessary for providing accurate assessment and improvement of current design standards.…”

Structural behaviour of cold-formed S700 high strength steel tubular members after exposure to fire

“…Also, it is recommended to improve the design accuracy of HSS tubular members under pure compression and pure bending, based on which the accuracy of design interaction curves can be improved. Meng and Gardner (2022) tested ten cold-formed CHS beam-columns under combined compression and bending, assessed the current European code and highlighted that the design predictions were conservative and scattered due to ignoring the beneficial effect of increased yield stress on the member stability. Table 2.5 summarises the previous tests on fabricated, hot-rolled and cold-formed HSS beam-column.…”