Structural behavior of built-up I-shaped high-strength cold-formed steel columns with edge-stiffened holes, unstiffened holes, plain webs, and batten reinforcement
Publication Name: Thin Walled Structures
Publication Date: 2026-01-01
Volume: 218
Issue: Unknown
Page Range: Unknown
Description:
Cold-formed steel (CFS) back-to-back channel sections are widely employed as load-bearing structural components due to their high strength-to-weight ratio and ease of fabrication. These sections are often perforated to facilitate service installations; however, the presence of holes alters stress distribution, reduces axial load capacity, and increases the complexity of structural analysis. To investigate these effects, a geometrically and materially nonlinear finite element (FE) model was developed and validated against experimental data from existing literature. Specifically, the validation results demonstrated a strong correlation, with the ratios of Finite Element Analysis (FEA) and Direct Strength Method (DSM) predictions to experimental findings being 1.001 and 1.003, respectively. These results indicate a high level of agreement between experimental data, FE analysis, and strength predictions according to the American Iron and Steel Institute (AISI) and the Australian/New Zealand Standards (AS/NZS). Subsequently, the validated FE model was utilized to perform an extensive parametric study involving 130 simulations to examine the influence of hole geometry, edge stiffeners, and batten reinforcement plates on the axial capacity of built-up CFS columns. The results indicate that unstiffened slotted holes lead to an approximate 10.3% reduction in strength, whereas edge-stiffened square holes contribute to a 2.7% increase in axial capacity. Additionally, batten-reinforced unstiffened rectangular holes and edge-stiffened rectangular holes were found to enhance strength by approximately 7.5% and 15.5%, respectively. Moreover, incorporating batten plate reinforcements in plain columns improved axial capacity by approximately 6%. These findings provide valuable insights into the structural behavior of perforated CFS built-up columns and highlight the effectiveness of hole stiffeners and batten reinforcements in mitigating strength reductions caused by perforations.
Open Access: Yes