Experimental and numerical study on influence of impact mass and velocity on failure mode of RC columns under lateral impact

• Published in: Engineering structures Vol. 314; p. 118416
• Main Authors: Sun, Jing-Ming, Chen, Hui, Yi, Fan, Ding, Ya-Bo, Zhou, Yun, He, Qing-Feng, Zhang, Wang-Xi, Yi, Wei-Jian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: Dynamic response; Failure mode; Impact loads; Numerical analysis; Pendulum test; RC column; Dynamic response; Failure mode; Numerical analysis; Impact loads; RC column; Pendulum test
• ISSN: 0141-0296
• DOI: 10.1016/j.engstruct.2024.118416

Reinforced concrete (RC) structures may encounter impact loads during service life, such as vehicle collisions, ship strikes, and explosions. Limited existing impact tests on RC columns and piers have yet to fully reveal the column impact performance and its relationship with structural or load parameters. To explore the effects of impact mass and velocity, which determine the impact energy, on the impact performance of RC columns, pendulum impact tests on nine RC columns were performed utilizing a specially designed loading setup. The test variables included the impact mass and velocity of the pendulum, as well as the slenderness ratio and stirrup ratio of the columns. During the tests, the impact force and velocity of the pendulum, as well as the axial force, displacement, and acceleration of the columns, were measured. Additionally, the damage evolution of each specimen was recorded using a high-speed camera. One-side shear failure, two-side shear failure near the impact point, and shear failure at the column bottom end were observed during the tests. The results indicated that, under similar impact energy, as the impact velocity increased, the specimens with the low stirrup ratio transitioned from one-side shear failure to two-side shear failure. An enhancement in the impact resistance of the columns was observed when the stirrup ratio was increased, or the slenderness ratio decreased. For the enhanced columns, shear failure was avoided at lower impact velocities; however, at the maximum impact velocity, end shear failure or one-side shear failure yet occurred. Additionally, a parametric analysis using LS-DYNA finite element software further clarified the effects of impact velocity and mass on the dynamic response and failure mode of RC columns. •Nine RC columns were tested to systematically evaluate effects of impact mass and velocity.•One-side shear failure, two-side shear failure and end shear failure were observed.•The transition in failure modes was examined through dynamic forces and energy analysis.•Obtained results hold significance for the structural design and assessment of RC columns under impact.