Mechanical behavior of Q690 high‐strength steel beams at room and elevated temperatures

Summary This paper investigates the mechanical behavior of Q690 high‐strength steel (HSS) beams at room and high temperatures by means of experimental and numerical analysis. First, simply supported and cantilever Q690 steel beams were tested under room and elevated temperatures. The test results indicated that the bearing capacity of the specimens in fire decreases sharply with the increase of temperature. Subsequently, finite element models were established and verified against the experimental results. Finally, a large amount of numerical analysis was carried out, and two formulae to estimate the bearing capacity of Q690 HSS beams under room and elevated temperatures were obtained. The results estimated by the formulae were compared with the test data and Eurocode 3, which proved that the proposed formulae are reliable enough for practical design.