Title: A Simplified Method to Predict Damage of Axially-Loaded Circular RC Columns Under Lateral Impact Loading

Author(s): Bin Liu, Wei Fan, Xu Huang, Xudong Shao, Lijing Kang

Publication: IJCSM

Volume: 14

Issue:

Appears on pages(s):

Keywords: circular column, axial load, simplifed model, residual deformation, fexural damage

DOI: 10.1186/s40069-020-00406-z

Date: 7/30/2020

Abstract:
Detailed fnite element (FE) models are often employed to predict the impact responses of reinforced concrete (RC) columns. However, they always require substantial investments of time and efort in modeling and analysis so that they are not widely used in practice, particularly in preliminary designs. Moreover, although some simplifed models have been established for beams and slabs under impact loading, few attempts have been made on modeling RC columns. For these reasons, this paper proposes a simplifed modeling method to accurately capture the impactinduced response and damage of circular RC columns. In the proposed method, a two-degree-of-freedom (DOF) system was used to describe the interaction between the impactor and the impacted column. The formulas, and procedure to estimate the force–deformation relationship with strain-rate efects were presented according to the section-based analysis. The infuence of the unloading stifness on the residual deformation was addressed, and the method to determine the unloading stifness of circular columns was proposed. Furthermore, a fber-based beamcolumn element modeling method was developed to estimate the force–deformation relationship of the columns with strain-rate efects. The proposed simplifed method was demonstrated by the drop-hammer impact tests to be capable of predicting the impact response of RC columns well. Its accuracy in the residual deformation is superior to that of the detailed FE simulation. Parametric studies were performed to investigate the damage characteristics of axially-loaded circular RC columns under various impact scenarios.