To overcome brittle failure in conventional cold-formed steel–concrete (CFS-C) corner columns, this paper used fiber-reinforced concrete to replace ordinary concrete, investigating failure mechanisms and performance through systematic numerical simulations. A finite element model (FEM) was established and validated by experiments, and the errors for ultimate capacity were within 10%. A series of numerical models was established for parametric analyses focusing on the effects of the parameters of polypropylene fiber (PF), carbon fiber (CF), steel fiber (SF), and bamboo fiber (BF) with different volume dosages and the thickness of cold-formed steel (CFS) on the axial compression ultimate capacity and corresponding displacement of CFS composite corner columns. The results indicated that (1) PF effectiveness was dependent on steel thickness: thicker steel suppressed micro-defects, activated the toughening potential of PF, and increased the ultimate capacity of the columns by 24.8%. (2) CF had a critical dosage of 0.4%: at this dosage, CF increased the column’s ultimate capacity by 14.1% through stress redistribution, while when the dosage exceeded this value, fiber agglomeration caused a reduction in the column’s strength, with a maximum decrease of 16.2%. (3) SF effectiveness showed a linear increase: at a dosage of 1.6%, SF formed a synergistic three-dimensional bridging network and generated a confinement effect, increasing the column’s ultimate capacity by 36.5% and displacement by 92.2%. (4) BF mainly improved the ductility of columns: through crack bridging and pull-out energy dissipation, BF increased column displacement by 33.2%. (5) The modified Eurocode 4 formula could reduce the calculation error of ultimate capacity from 6.3% to within 1%. The findings guide optimal fiber selection and dosage in practice, promoting such columns’ use in seismic and load-bearing structures.

This study presents experimental investigations of the flexural bearing capacity of the lower load-bearing structures of pull-up cantilever scaffolds with adjustable steel tie rods. First, load-bearing structures with three different specifications are tested to analyze their primary failure modes and failure mechanisms. The experimental results are then simulated and validated using a finite element analysis (FEA) method. Subsequently, an extended parametric analysis is performed numerically, and a simplified calculation formula is derived through nonlinear curve fitting to evaluate the load-bearing capacity. Finally, the effects of the transverse spacing of the vertical rods, the length of the cantilever beams, and the spacing of the hanging ears on the flexural bearing capacity of the structures are analyzed.

Blasts, vehicle collisions, and other unexpected incidents may cause lateral impacts on building structures, which threaten their safety. This paper investigates the impact resistance of cold-formed steel (CFS) L-shaped built-up columns (LBC). Firstly, a finite element model (FEM) was established and validated through experiments conducted by the authors. Then, a parametric analysis was conducted to quantify the effects of axial compression ratio, impact velocity, and dimensions on the impact response. The results indicated that: (1) The peak lateral impact force of the specimens presented a significant nonlinear trend with increasing axial compression ratio, and an optimal axial compression ratio was found as about 0.3. (2) Higher impact velocity intensified both force and displacement responses of the specimens, and both lateral impact peak force and maximum displacement increased significantly with the impact velocity. When the impact velocity rose from 3.13 m/s to 6.26 m/s, the peak force and maximum displacement increased by an average of 38.2% and 96.5%, respectively. (3) Increasing the cross-sectional dimensions and steel thickness, and reducing screw spacing, could significantly enhance the impact resistance and deformation capacity of the specimens. This study reveals the failure mechanism of such members and the laws of parameter influence, which can be used for impact design of CFS-LBC.