Impact Behaviors of CFT and CFRP Confined CFT Stub Columns

Concrete-filled steel tube (CFT) structures are widely used in various types of buildings and bridges. Confined concrete tube (CCFT) is a new type of structural column originally proposed in previous work. This paper reports the impact testing results of the CFT and carbon fiber reinforced polymer (CFRP) confined CFT stub columns under different impacting energy levels, conducted using a large-capacity drop-hammer machine. The time history curves of impacting force and deformation time history curves as well as failure patterns are investigated. The results indicate that the failure patterns are related to the impact energy. Increasing the thickness of the steel tube and providing additional transverse confinement by CFRP can enhance the impact-resistant behavior. Finally, the dynamic analysis software ANSYS/LS-DYNA is used to simulate the impact behaviors of the CFT and CCFT specimens, and the simulation results are reasonable compared with the test results. DOI: 10.1061/(ASCE)CC.1943-5614.0000294.(C) 2012 American Society of Civil Engineers.