Simplified impact force models for novel FRP-steel–concrete composite columns under axial impact loading

Abstract

This study aims to investigate the axial impact resistance of FRP tube-confined concrete-encased cross-shaped steel column (FCCSC). The numerical simulations were conducted utilizing the ABAQUS software. The finite element (FE) models developed in this study were validated and upgraded by fitting the relevant test data of FRP-confined concrete-filled steel tube (FCFST). Subsequently, a significant number of models were established and executed with four variable parameters, namely impact mass, impact velocity, concrete strength and FRP tube thickness. Based on the analysis results, typical axial impact states were summarized and defined. Then, the simplified impact force time history models were developed for predicting the dynamic responses of FCCSCs subjected to axial impact loads. The dynamic damage index for axial impact resistance and the corresponding design flow of FCCSCs also have been proposed.