Effect of Uncertainty in Localized Imperfection on the Ultimate Compressive Strength of Cold-Formed Stainless Steel Hollow Sections

Abstract

Stainless steel has excellent corrosion resistance properties, considerable long-term durability, and good mechanical strength. Hollow sections are a versatile and efficient form for construction applications. The use of cold-formed stainless steel rectangular hollow section (RHS) and square hollow section (SHS) in construction industry grasps the attention of designers conceiving long-term, cost-effective structures. For cold-formed RHS and SHS, localized imperfection (ω) resulting from rolling and fabrication process is inevitable. ω has inherent variability and has no definitive characterization. In this paper, statistical analysis of the maximum value of ω collected from available experimental data is conducted. A new approach utilizing Fourier series to generate the three-dimensional (3D) models of members with random ω is proposed. Probabilistic studies based on the proposed 3D models are then carried out to evaluate the effect of uncertainty in ω on the ultimate compressive strength of stainless steel columns with cold-formed RHS and SHS. A total of 21 columns that are prone to local buckling reduction are studied. The results show that uncertainty in ω has a considerable influence on the columns with relatively higher cross-sectional slenderness.

Investigation of a Method for Strengthening Perforated Cold-Formed Steel Profiles under Compression Loads

“…For each specimen type, at least three tests were carried out as recommended by the Australian Racking code (AS4084: 2012) [33]. The reason for the different ultimate values for these three tests of each specimen can be attributed to the fact that upright elements have different initial geometrical imperfections associated with the manufacturing processes [34].…”

Geometrically non-linear analysis with stiffness reduction for the stability design of stainless steel structures: Application to members and planar frames

“…A B21 box section has 5 default Simpson integration points in the two walls of the section. Two iterative methods, the Newton method (load controlled) [24] and Arc-length method [25] are employed to compute the solution of nonlinear equilibrium equations. Based on preliminary mesh convergence study, the adopted mesh density is 100 elements per member.…”

Flexural stiffness reduction for stainless steel SHS and RHS members prone to local buckling

“…1.). Localized imperfections, which are induced from rolling and fabrication process, have sufficient variability and have no definitive characterization [29]. Therefore, it is necessary to evaluate the sensitivity of the extended stiffness reduction factor (in conjunction with GNA) to random ω (both the shape and magnitude of ω varied randomly).…”

“…In the current paper, the value of ω considered in the ρ factor is conservatively taken as the mean value of the maximum localized imperfection (ω max ) collected from reported tests. Statistical analysis of ω max of a total of 161 cold-formed stainless steel RHS and SHS members has already been provided in [29,36]. The study of Shen [36] showed that the mean value of ω max of the collected samples is 0.185.…”