The provides distinct formulas based on moment of inertia

The predominant buckling mode of
cold-formed steel member is local. Several researchers found that edge and
intermediate web stiffener plays significant role to enhance local buckling
strength of cold-formed steel members. Selection of shape of edge and intermediate
stiffener found to be tricky job for the researchers. Different codes provides
distinct formulas based on moment of inertia for providing edge and
intermediate stiffener. IS: 801-1975, BS 5950-5: 1998, AISI S-100-2007, AS/NZS
4600: 2005 have been studied to develop idea about shape of edge and
intermediate stiffener. Six models including base model has been selected as
per limits for pre-qualified columns given in Table 1.1.1-1 in Appendix 1 of
AISI S-100-2007. Lipped channel section having length of 0.5 m has been
selected for linear buckling analysis by keeping constant depth of web as 100
mm and width of flange as 50 mm. BS 5950-5: 1998 code have been used to select
shape of edge stiffener as per Clause 4.6 and intermediate web stiffener as per
Clause 4.7.1 for base model. Quadrilateral shape of intermediate web stiffener
have been selected for the analysis. The material preferred for the analysis
have the modulus of elasticity (E) and poison’s ratio are 2.05E5 MPa and 0.3
respectively. Models were analysed by varying shape by changing width and depth
of intermediate web stiffener for all models related to base model having
constant lip length as 10 mm. The results related to provision of edge
stiffener and intermediate web stiffener has been given in Table no. 1 and 2
respectively. It has been observed from the results, BS 5950-5: 1998 code is
conservative for provision of edge stiffener and AS/NZS 4600: 2005 code is
conservative for provision of intermediate stiffener comparatively. If compared
with base model, there is no significant variation in critical buckling
strength, even after significant variation in moment of inertia of intermediate
stiffener.