Numerical Modeling of Recycled and Normal Aggregate CFRP-Strengthened Concrete-Filled Steel Columns Subjected to Lateral Impact

Abstract

This paper presents 3D nonlinear finite element analyses on concrete-filled steel-tube (CFST) columns subjected to lateral impact loading by considering concrete type, projectile configuration, and strengthening with carbon fiber-reinforced polymer (CFRP) laminates. The numerical outputs were validated against the experimental results with good agreement, in terms of load-displacement trace and deformation mode. Using the validated models, further studies were undertaken to examine the influence of various parameters on the impact response, which include the material property, D/t (external diameter/wall thickness) ratios, and CFRP coverage area. The numerical predictions show that increasing the impact energy enables the columns to exhibit a higher impact force for all CFST columns studied. Reducing the D/t ratio and increasing the steel-tube strength led to an increase of the impact force and a decrease of the displacement, due to the enhanced stiffness of the tube. The results also indicate that increasing the CFRP wrapping from one-third coverage of the column surface to two-third coverage increases the impact peak load and columns stiffness but reduces the lateral displacement, while the full CFRP wrapping has almost the same enhancement as does the two-third coverage.