Cold-formedmembers are thin in nature, hence predominant mode of failure found to belocal. Edge and intermediate stiffener plays important role to improve localbuckling strength of the member. Various parameters influences the bucklingload of cold-formed member hence it is necessary to recognize influenceof these parameters on critical buckling load under axial compression. Fromliterature, it is observed that, influence of parameters on buckling load, likeshapes of intermediate stiffener, thickness of steel plate, width of flange,depth of intermediate web stiffener and length of lip for cold-formed lippedchannel section has been not studied in detail. In this paper, the study havebeen conducted on 924 models of lipped channel section and selected as percriteria given in AISI -2007. In present study, the linear buckling analysishas been performed on various shapes of triangular, trapezoidal andquadrilateral intermediate stiffener by varying depth of intermediate stiffenerfrom 3 to 36 mm with constant thickness as 1.50 mm, thickness of steel platefrom 1.5 to 6 mm with constant ratio of depth of triangular intermediatestiffener to depth of web or flange as 0.
06, flange width from 50 to 90 mm with constantdepth of triangular intermediate stiffener to depth of web or flange as 0.06,width of triangular, trapezoidal and quadrilateral intermediate web stiffenerfrom 2 to 20 mm with constant ratio of depth of intermediate stiffener to depthof web as 0.12 and length of lip from 3 to 24 mm for plain lipped channelsection.
The study have been conductedon various models of lipped channel sections by varying lengths from 0.5 m to6.0 m. The member has been analysed with both end fixed and allows translationin the lateral direction. The linear buckling analysis have been performed onvarious models by using finite element software ABAQUS. Local, distortional andEuler’s failure modes were observed for critical elastic buckling.
From thestudy, it has been observed that, the shape of intermediate stiffener areeffective up to 2.50 m length of member and beyond that the effectivenessdiminishes. However, as compared to triangular and trapezoidal shape thequadrilateral shape intermediate web stiffener imparts larger resistance tobuckling. Increase in thickness of steel plate and flange width reduces theeffectiveness of intermediate web stiffener for shorter members i.e. 0.
5 and2.0 m length of member and for larger length, intermediate web stiffener arenot effective and no effect of thickness and flange width has been observed.Increase in depth of triangular, trapezoidal and quadrilateral intermediatestiffener reduces the effectiveness of intermediate web stiffener after 6 mm.
Lip length up to 9 mm is effective for the length up to 2.5 m long member andup to 6 mm for 3.0 m long member.