Web Crippling Behaviour of Cold-Formed Carbon Steel, Stainless Steel, and Aluminium Lipped Channel Sections with Web Openings

Abstract

This paper reviews the research advancements and design practices related to the structural web crippling response of lipped Cold-Formed (CF) carbon steel, stainless steel, and aluminium channels with web perforations. The web crippling response differs among each material based on the non-linear stress-strain characteristics and degree of strain hardening. Therefore, the reduction in the web crippling strength of web-perforated CF channel sections made of different materials may not be equivalent. The research activities surrounding the web crippling response of CF channels with and without web openings were reviewed initially. Despite the limited design provisions given in the international specifications for the web crippling design of lipped CF channels with web openings, web crippling studies conducted across the world have developed suitable design equations in the form of reduction factors. Past research studies have substantially captured the web crippling response of carbon steel channels with web openings while that of stainless steel and aluminium are limited, as identified in this paper. Lastly, numerical models were developed for simulating the web crippling behaviour of lipped CF carbon steel, stainless steel, and aluminium channels with web opening and validated with past experimental data, with a view for developing unified design guidelines.

Design of aluminium Sigma sections for web crippling behaviour under Interior Two Flange (ITF) load case

“…Sigma section was modelled using S4R shell elements while bearing plates were modelled using R3D4 rigid elements. In terms of meshing scheme, 5 mm x 5 mm mesh size was used in flat sections of sigma section whereas 1 mm x 5 mm mesh scheme was used in corner regions of sigma section based on the past research studies [11][12][13][14][15][16][17][18]. Coarser mesh scheme of 10 mm x 10 mm used for bearing plates.…”

Web crippling behaviour and design of aluminium SupaCee sections

“…Major parts of the FE model are SupaCee section and bearing plate. SupaCee section was modelled using 5 mm x 5 mm mesh considering past similar research studies [9][10][11][12][13][14][15]. However, 1 mm x 5 mm mesh size was opted for the corner regions.…”