Dynamic performance of flexure-failure-type rectangular RC columns under low-velocity lateral impact

Abstract

This paper presents an experimental investigation of the dynamic moment-rotation relationship of flexure-critical RC columns under low-velocity impact. Impact tests of RC columns were conducted and an acceleration measurement scheme was proposed to estimate the inertial force of the column during the impact. The true flexural strength-rotation relationships of RC columns under impact loading were obtained, which indicates that the flexural strength and ultimate deformation of the column increased due to the strain rate effects when compared with the quasi-static results simultaneously conducted in this paper. The influence of strain rate and main structural parameters on the moment-rotation relationship of the RC column was analyzed. Finite element (FE) techniques to predict the impact resistance of RC columns were then validated based on the experimental results, followed by a parametric study to investigate the effects of impact velocity, longitudinal reinforcement ratio and axial force ratio on the moment-rotation relationships of RC columns. Finally, experimental and numerical results were used to develop an empirical model to predict the dynamic moment-rotation relationship of bridge piers under low-velocity impact. These findings drawn from the experimental and numerical investigations can facilitate to predict the dynamic moment-rotation relationship of RC columns subjected to vessel impacts.