Abstract：Based on the drop weight impact tests, the mechanisms of deformation, cracking and fracture for concrete-filled steel tubular (CFST) members are investigated. The experimental results show that the CFST members experience the prominent local response stage before cracking, with the local depression at the impact position and the local buckling at the support section. Hence, the critical cracking energy is mainly determined by the energy dissipations of global deformation and local damage. Based on the numerical simulations, the cracking evaluation curve considering the impact mass and impact velocity is obtained. From the energy viewpoint, the cracking evaluation model considering the local energy dissipation is established, and the effects of impact location, concrete strength, steel strength and steel ratio on the cracking evaluation model are investigated. The research results show that the impact energy which makes the CFST member in critical cracking state is not a constant value. For the case of high impact velocity and low impact mass, the more obvious local response of the CFST member produces more local energy dissipation, and the critical cracking energy increases. With the increase of the impact mass, the cracking evaluation model converges asymptotically to a horizontal line, which corresponds to the minimum critical cracking energy. According to the relationship between the impact energy and the cracking evaluation model, the local damage and cracking state of the CFST member can be evaluated. The change of the impact location may significantly affect the cracking evaluation model. The increases of the steel strength and steel ratio can effectively improve the performance of resisting impact cracking of the CFST members, but the improvement of the concrete strength has little effect on the cracking state of the CFST member.
王路明 刘艳辉 赵世春 赵一超 康翔杰. 侧向低速冲击作用下钢管混凝土构件开裂评估模型及影响因素研究[J]. 土木工程学报, 2022, 55(3): 7-17, 35.
Wang Luming Liu Yanhui Zhao Shichun Zhao Yichao Kang Xiangjie. Study on evaluation model and influencing factors for cracking of concrete-filled steel tubular members subjected to lateral low-velocity impact. 土木工程学报, 2022, 55(3): 7-17, 35.
