Abstract To meet specific design requirements or achieve superior structural performances, a new type of concrete-filled steel tubular (CFST) composite structure called as concrete-filled double-tube (CFDT) was proposed in recent years. Despite intensive studies on structural performances of CFDT members under various loading conditions, very limited investigations on impact responses of CFDT members can be found in literature. During the service life structural members may be subjected to extreme loads such as impact load, therefore the investigation on impact responses of CFDT members is essential for impact resistant design and assessment. This paper presents experimental study and finite element analysis (FEA) results of lateral impact responses of circular CFDT members. A total of twelve circular CFDT specimens with various parameters are tested by utilizing a drop hammer impact system. The damage modes, impact forces, displacement responses and energy absorption capacities of CFDT members from the impact tests are evaluated and compared, followed by numerical simulations using explicit software ABAQUS. With the verified numerical models, the damage evolution of each component and its contribution to impact loading resistance are extracted and analysed. In addition, the performances of CFDT and common CFST members under impact loading are compared.

中文翻译：

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圆形双管混凝土（CFDT）构件横向冲击响应研究

摘要 为了满足特定的设计要求或实现优越的结构性能，近年来提出了一种新型的钢管混凝土（CFST）复合结构，称为钢管混凝土（CFDT）。尽管对 CFDT 构件在各种载荷条件下的结构性能进行了深入研究，但文献中对 CFDT 构件的冲击响应的研究非常有限。结构构件在使用寿命期间可能会承受冲击载荷等极端载荷，因此对CFDT构件的冲击响应研究对于抗冲击设计和评估至关重要。本文介绍了圆形 CFDT 构件横向冲击响应的实验研究和有限元分析 (FEA) 结果。使用落锤冲击系统测试了总共十二个具有各种参数的圆形 CFDT 试样。评估和比较来自冲击试验的 CFDT 构件的损伤模式、冲击力、位移响应和能量吸收能力，然后使用显式软件 ABAQUS 进行数值模拟。使用经过验证的数值模型，提取和分析每个部件的损伤演变及其对抗冲击载荷的贡献。此外，还比较了CFDT和普通CFST构件在冲击载荷下的性能。使用经过验证的数值模型，提取和分析每个部件的损伤演变及其对抗冲击载荷的贡献。此外，还比较了CFDT和普通CFST构件在冲击载荷下的性能。使用经过验证的数值模型，提取和分析每个部件的损伤演变及其对抗冲击载荷的贡献。此外，还比较了CFDT和普通CFST构件在冲击载荷下的性能。