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This paper presents the experimental and numerical studies in the investigation of the concentrated compressive behaviors of cold-formed steel-foam concrete composite wall. The failure modes, load–displacement curves, and load–strain curves of the specimens were obtained from the experiments. The infilled specimen failed due to distortional buckling of the end stud and cracking of the concrete near the corner of the wall. The strength of the high strength cold-formed steel was not being fully utilized. A finite element model was established by ABAQUS software and validated by the test results to investigate the effect of the concrete strength, steel strength, the spacing between stud openings, and the thickness of the concrete protective layer on the behaviors of the composite wall. The results indicate that the improvement of concrete strength has the most obvious effect on the bearing capacity of the composite wall, while the changes in steel strength, concrete cover thickness, and hole spacing have limited effects. [ABSTRACT FROM AUTHOR]

This paper presents the experimental, numerical, and theoretical studies aimed at investigating the fire behaviors of high strength Q690 steel T-stub connections. The experiments determined failure modes, load–displacement curves, ultimate displacement, ductility factors, and load capacities of the specimens at elevated temperatures. The rupture of the flange disappeared at temperatures exceeding 600 °C. A finite element model was established using ABAQUS software, validated by the experimental results, to explore the effect of bolt preload and bolt grade on the fire behaviors of T-stubs. The first yield resistance derived from experimental and numerical findings was compared with EC3 predictions, highlighting a severe underestimation by EC3 for high-strength steel T-stubs with thin-walled flanges. A theoretical model was subsequently proposed and validated against numerical and experimental outcomes, serving as the basis for a novel design method. This model accurately anticipates the progression of the plastic hinge line and the first yield resistance, suggesting the use of 2.0% yield strength of high-strength steel to calculate the first yield resistance of steel T-stubs. • Tension test on high strength steel T-stub connections at elevated temperature were carried out. • Finite element model on T-stub connection were established and validated by test data. • Parametric studies were conducted to quantitatively assess the influence of key factors on capacity of T-stub connection. • The load capacity of T-stub connection predicted by EC3 were evaluated and design methods were proposed. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical studies to investigate the fire behavior of high strength steel (Q690 and Q960) shear connections. The load-displacement curves, failure modes, and load capacities, including the slip load and ultimate load of the specimens at elevated temperatures were obtained from experiments. A finite element model was established by ABAQUS software and validated by the test results to investigate the effect of the friction coefficient and the assembly form of the bolt on the shear behavior. The numerical results of load capacity were compared with that predicted by EC3, AISC 360–16, and GB50017. Parametric studies were conducted to investigate the effect of the slip load on the ultimate load at ambient temperature, and design methods were proposed considering the friction coefficient and preload values. The research shows that the slip load decreases more rapidly than the ultimate load at elevated temperatures. The critical temperature from brittle failure to ductile failure is approximately 500 °C. The load capacity predicted by AISC 360–16 is accurate, while EC3 and GB50017-2017 predict conservative load capacity. The effect of the bolt load and friction coefficient cannot be ignored for high strength steel shear connections. In order to investigate the fire behavior of high strength steel (Q690 and Q960) shear connections, experimental and numerical studies were presented in this paper. The load-displacement curves, failure modes, and load capacity, such as the slip load and ultimate load of the specimens at elevated temperature were obtained from the experiment. Finite element model was established by ABAQUS software and validated by the test results to investigate the effect of the friction coefficient and the assemble form of the bolt on the shear behavior. The analytical results of load capacity were compared with that predicted by EC3, AISC 360–10, and GB50017. Parametric studies were conducted to investigate the effect of the slip load on ultimate load at ambient temperature, and design methods were proposed considering the friction coefficient and preload values. The research shows that the slip load decreased more rapidly than the ultimate load. The failure temperature from brittle failure to ductile failure is approximate 500 °C. The stiffness of the connection deceases significantly due to the eccentric assembly form of the bolt. The load capacity predicted by AISC 360–10 is accurate, while EC3 and GB50017-2017 predict conservative load capacity. [Display omitted] • Tests on shear capacity of high strength steel connections at elevated temperature were carried out. • Finite element models on shear connection were established and validated by test data. • Parametric studies were carried out to quantitatively assess the influence of key factors on shear capacity of connection. • The shear load capacity of connection predicted by AISC 360–10，EC3 and GB50017-2017 were evaluated. [ABSTRACT FROM AUTHOR]