Experimental and numerical study of axially loaded reinforced concrete columns and frame columns under lateral impact loading

Abstract

Pendulum impact tests were conducted on a reinforced concrete (RC) frame column and four RC free-standing columns. The effects of the axial compression ratio and reinforcement ratio on the impact resistance of the columns were compared using the dynamic time curves of framed and freestanding columns under impact. The test results show that for the same impact load, although the presence of axial loads can play a positive role (e.g., reducing the residual displacement), it may lead to more severe local damage. In addition, compared with free-standing columns, frame columns can be considered as a protective structure because of their greater lateral stiffness and stronger crashworthiness. The corresponding finite element models are developed, and the influence of the axial loads on the cross-section force responses under impact excitation was deeply explored. Axial loads can significantly affect the distribution of moment, shear force, and damage to the column.