BEHAVIOUR OF LOCALLY DAMAGED Q355 STEEL EQUAL ANGLES SUBJECTED TO COMPRESSION

Steel angles in transmission towers may experience corrosion in the service life due to bad exposure conditions. However, limited experimental results are available about the remaining load capacity of corroded steel angles in compression at present. This paper presents experimental tests, numerical simulations and design method of steel angles with local damages at the mid-height or end induced by corrosion. Five groups of steel angles with different depths of local damages at different locations were tested under axial compression in the experimental programme, and the load capacity and failure mode of steel angles were obtained. Numerical models are developed and validated using test data, and parametric studies are conducted to investigate the influence of depth and slenderness of steel angles on ultimate load. Moreover, design equations are developed for locally damaged steel angles, and comparisons with numerical results show yield reasonably accurate estimations of the ultimate load. Comparisons are also made between the calculated result using the developed equation and existing design curves in the relevant code to demonstrate the effect of local damage on the buckling coefficient of steel angles. It shows that the local damage at the mid-height or the end of steel angles could significantly reduce the buckling coefficient, and therefore, it has to be considered when evaluating the ultimate load of steel angles in transmission towers in service.