Detailed finite 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 effort in modeling and analysis so that they are not widely used in practice, particularly in preliminary designs. Moreover, although some simplified 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 simplified modeling method to accurately capture the impact-induced 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 effects were presented according to the section-based analysis. The influence of the unloading stiffness on the residual deformation was addressed, and the method to determine the unloading stiffness of circular columns was proposed. Furthermore, a fiber-based beam-column element modeling method was developed to estimate the force–deformation relationship of the columns with strain-rate effects. The proposed simplified 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.

中文翻译：

---

横向冲击荷载作用下轴向加载圆形钢筋混凝土柱损伤预测的简化方法

详细的有限元 (FE) 模型通常用于预测钢筋混凝土 (RC) 柱的冲击响应。然而，它们总是需要在建模和分析方面投入大量时间和精力，因此它们在实践中没有得到广泛应用，特别是在初步设计中。此外，虽然已经建立了一些梁和板在冲击载荷下的简化模型，但很少尝试对 RC 柱进行建模。由于这些原因，本文提出了一种简化的建模方法，以准确捕获圆形 RC 柱的冲击引起的响应和损坏。在所提出的方法中，使用二自由度 (DOF) 系统来描述撞击器和被撞击柱之间的相互作用。公式，根据基于截面的分析，提出了估计力-变形关系与应变率效应的程序。研究了卸载刚度对残余变形的影响，提出了确定圆柱卸载刚度的方法。此外，开发了一种基于纤维的梁柱单元建模方法来估计具有应变率效应的柱的力变形关系。通过落锤冲击试验证明了所提出的简化方法能够很好地预测 RC 柱的冲击响应。它的残余变形精度优于详细的有限元模拟。