Variable and constant amplitude testing of concrete in-filled steel tube columns

This paper reports numerical study on the behaviour of Concrete in-filled steel tube (CFT) columns and Steel fibre reinforced concrete filled steel tube (SCFT) columns subjected to variable amplitude loading along with constant axial load. The test parameters are diameter to thickness ratio of steel tube and types of in-filled concrete namely plain cement concrete and Steel fibre reinforced concrete. The results of numerical study were verified against comprehensive set of experimental data of hysteresis plots; ductility factor; energy absorption capacity; loads at failure and crack patterns at failure available in the companion paper of the corresponding author. The verified finite element model has been used for predicting the ductility factor and energy absorption capacity of CFT and SCFT columns. Irrespective of D/t ratio and type of in-fill, the decrease in energy absorption capacity with increase in drift ratio from 2% to 4% is about 1.4 to 1.8 times and with increase in drift ratio from 4% to 6%, the decrease in energy absorption capacity is about 1.2 to 1.9 times. (C) 2019 Elsevier Ltd. All rights reserved.