Compression tests of cold-formed plain and dimpled steel columns

This paper presents compression tests of cold-formed plain and dimpled steel columns. A series of compression and tensile tests were conducted on plain and dimpled steel of different geometries. For each group of geometries the source of material for both the plain and dimpled steel columns was taken from a single coil. Within each group the sections were fabricated either by press-braking or cold-rolled forming. The buckling and ultimate strength of the columns was investigated. The change in strength of the dimpled columns resulting from the cold working associated with the dimpling process was also considered. This paper contains the results obtained when comparing the test strengths of short plain and dimpled steel columns using a compression test. In outlining the work the test setup and testing procedure will be described. Enhancements in buckling and ultimate strengths were observed in the dimpled steel columns-caused by the cold-work of the material during the dimpling process. The results showed that the buckling and ultimate strengths of dimpled steel columns were up to 33% and 26% greater than plain steel columns, respectively.

► Compression tests and evaluation of plain and dimpled steel columns were reported.
► A testing method was established to determine strengths in dimpled steel columns.
► The strengths of dimpled columns were significantly greater than plain columns.
► Strength increase is a result of plastic deformation developed during the process.