考虑不同强度钢材动态本构模型差异的钢管混凝土侧向抗冲击性能有限元分析

High-strength materials are the trend of modern building structures, while using the dynamic constitutive models of normal structural steel directly deduce the dynamic mechanical properties of high-strength CFST members may bring a large deviation.The dynamic constitutive models and relevant strain rate effect for various structural steels were discussed in this paper, and a refined finite element model of CFST member subjected to lateral impact loading was verified by test results. Based on which, the transverse impact behaviors of circular and square CFST were deeply investigated by FEA when employing different rate-dependent models of various grades of steels, and then the influence of yield strength and relevant dynamic constitutive models was studied. FEA results show that the lateral impact resistance of CFST increases when using higher strength of steel pipe. However, for the analyses regarding high-strength CFST components against impact loading, using the dynamic model based on ordinary-strength steel directly will overestimate the impact force plateau value and underestimate its mid-span displacement compared with the real rate-dependent models for steels.Therefore, it will significantly overestimate the impact bearing capacity of CFST, and such overestimation will further intensify as the strength of steel and the impact energy increase.The refined finite element analyses were recommended for CFST members with moderate and high-risk consequences.