Residual bearing capacity of hybrid fibre-reinforced polymer-ultra-high-performance concrete-steel double-skin tubular columns after impact loading

This study investigates the residual mechanical properties of a hybrid fibre-reinforced polymer (FRP)–ultra-high-performance concrete (UHPC)–steel double-skin tubular column (DSTC) subjected to lateral impact load. Lateral impact tests were conducted on six CFRP pipe–UHPC–steel tube composite hollow columns and one concrete steel tube hollow column. The residual mechanical properties and failure modes of the CFRP pipe–UHPC–steel tube composite hollow columns under lateral impact loads were analysed. The influence of different core concrete strength grades, CFRP winding layers, and inner steel tube diameters on the failure mode and residual bearing capacity of the steel tube composite hollow columns when the specimens were subjected to transverse impact loads was discussed. The ABAQUS finite element software was used to analyse the new composite columns. The simulation and test results were found to be consistent. The results showed that increasing the core concrete strength grade and inside diameter could improve the residual bearing capacity of steel tubes.