Effect of battens’ spacing on the cyclic response of built-up columns

Abstract

Built-up columns have been widely used in buildings and bridges. However, despite wide application in steel construction, the seismic design of these columns has not been covered in either the design codes or the literature. On the other hand, past earthquakes have shown that built-up battened columns have been vulnerable to seismic actions. Therefore, it is crucial to investigate the seismic response of these columns and determine their governing failure mode, deformation, and bending moment capacity. This study investigated the effect of battens’ spacing on the cyclic response of built-up columns through experimental works and numerical simulations. Four columns with different batten spacing and chord distances were constructed and subjected to quasi-static cyclic loading. Besides, 24 built-up battened columns with different batten spacing, chord distances, and axial forces were simulated in ABAQUS software and subjected to similar cyclic loading. The obtained results indicated that the bulging of chord webs and the local buckling of chord flanges were the main reason for the failure of columns. Besides, the batten spacing significantly affected the bending moment capacity of built-up columns. Moreover, because of local buckling in flanges, built-up columns did not reach their plastic moment capacity. It was also observed that design codes’ limitations for batten spacing were not conservative and did not result in a similar safety margin for the bending moment capacity of built-up columns.