Cold-formed [7] performed experimental study on several column

Cold-formed steel is generally used in construction
industry due to its various benefits over hot rolled steel. Cold-formed steel
structures are gaining acceptance due to its availability in various shapes and
sizes with attractive colour coating. Various national codes like IS: 801 – 1975
(Indian) 1, AISI -2007 (American) 2, AS/NZS 4600:2005 (Australian and New
Zealand) 3 and Euro code 3 (part 1.3):
(2006) (European Union) 4 are available
for the design of cold-formed structures. Considerable
research work has been done on cold-formed steel structures since 1939. Professor
George Winter has done significant revolutionary work in this field and also
known to be “father of cold-formed steel” 5.
Cold-formed members are thin and hence problem of local and distortional
buckling usually governs the buckling strength. To improve buckling capacity of
cold-formed members, edge stiffeners known as lip along with intermediate
stiffener to web or flange of section are provided which makes the shape
complex. Due to complex shapes of cold-formed members it is difficult to predict
exact failure modes beforehand. To understand appropriate behaviour of
cold-formed steel under compression, significant amount of research has been
conducted by many researchers. Rasmussen and Hancock 6 performed compression tests on square and
circular stainless steel tubes for short as well as for long columns. They recommend
the design procedure for cold-formed stainless steel structural members.
Dhanalakshmi and Shanmugam 7 performed
experimental study on several column specimens, to study the behaviour and
ultimate load capacity of non-perforated and perforated equal-angle cold-formed
steel stub columns. They recommend simplified design formula to determine
ultimate load carrying capacity based on parametric study. Popovic et al. 8 performed number of compression tests on
cold-formed steel equal angles with slender cross section. The angles were
tested with pinned end boundary condition and loaded axially with eccentric
loading, which causes bending parallel with leg. The test results were compared
with Australian and American design specifications for cold formed and
hot-rolled steel structures, in addition with ASCE standard.