Cold-formed steel is generally used in constructionindustry due to its various benefits over hot rolled steel. Cold-formed steelstructures are gaining acceptance due to its availability in various shapes andsizes with attractive colour coating. Various national codes like IS: 801 – 1975(Indian) 1, AISI -2007 (American) 2, AS/NZS 4600:2005 (Australian and NewZealand) 3 and Euro code 3 (part 1.3):(2006) (European Union) 4 are availablefor the design of cold-formed structures. Considerableresearch work has been done on cold-formed steel structures since 1939. ProfessorGeorge Winter has done significant revolutionary work in this field and alsoknown to be “father of cold-formed steel” 5.
Cold-formed members are thin and hence problem of local and distortionalbuckling usually governs the buckling strength. To improve buckling capacity ofcold-formed members, edge stiffeners known as lip along with intermediatestiffener to web or flange of section are provided which makes the shapecomplex. Due to complex shapes of cold-formed members it is difficult to predictexact failure modes beforehand. To understand appropriate behaviour ofcold-formed steel under compression, significant amount of research has beenconducted by many researchers. Rasmussen and Hancock 6 performed compression tests on square andcircular stainless steel tubes for short as well as for long columns. They recommendthe design procedure for cold-formed stainless steel structural members.Dhanalakshmi and Shanmugam 7 performedexperimental study on several column specimens, to study the behaviour andultimate load capacity of non-perforated and perforated equal-angle cold-formedsteel stub columns.
They recommend simplified design formula to determineultimate load carrying capacity based on parametric study. Popovic et al. 8 performed number of compression tests oncold-formed steel equal angles with slender cross section. The angles weretested with pinned end boundary condition and loaded axially with eccentricloading, which causes bending parallel with leg.
The test results were comparedwith Australian and American design specifications for cold formed andhot-rolled steel structures, in addition with ASCE standard.