Effect of batten plates on the unlipped channel CFS built- up column under axial compression

Abstract

The behaviour of unlipped built-up CFS columns with batten plates is discussed in this article. The column consisted of two CFS channel section positioned back – to – back and close – to – close arrangement at constant distance of 20 mm apart. Batten plates of varying numbers from 0 to 3 were attached to the two channel sections. Channel sections were formed by brake-pressing of flat plate of 2 mm thick. All the column specimens of height 800 mm with pin – ended condition were tested under universal testing machine for compressive load. The paper documented the built-up column strength, load-axial shortening and load-micro strain relationships. Furthermore, the failure modes and buckling behaviour were compared with the finite element model developed using ANSYS and are agreeable. Test strengths were compared with the design strengths calculated in accordance with AISI Code, which implies that DSM specification is unconservative in predicting the ultimate strength of the built-up column experiencing in overall flexural buckling. Thus, increase in the number of batten plates from 0 to 3, increases the load carrying capacity of built-up columns with back – to – back and close – to – close channel arrangement by 7.3 % and 16.2 % respectively.