Reliability analysis of perforated cold-formed steel members in compression

Resumo

Cold-formed steel (CFS) members have been widely used in residential, industrial and commercial
buildings as primary load bearing structural elements due to their advantages such as higher strength to weight
ratio over other structural materials such as hot-rolled steel and concrete. CFS members are made of thin steel
sheets and hence they are more susceptible to various buckling modes. CFS with perforations are commonly used
in construction industry for example in residential construction and also low-rise buildings. This paper shows a
study of the level of reliability of perforated CFS members, based on AISI code, in order to adapt Brazilian code.
The aim of this study is the assessment of the reliability index β for a variation of the nominal live-to-dead load

ratios as well as comparison of the value found considering different load combinations. A test database of cold-
formed steel columns concentrically loaded was assembled and test-to-predicted statistics were obtained for the

Direct Strength Method (DSM). The first order reliability method (FORM) is used to calculate the reliability index
β. Based on the results of the reliability index, it was found that the required safety level was not reached when the
target reliability index of 3.0 was established.