Abstract: The dynamic control equation of a new prestressed partially concrete-filled rectangular steel tube (CFRT) beam can be derived based on D’Alembert’s principle. It is used to infer the theoretical results of the dynamic characteristics for the prestressed CFRT beam. Additionally, the finite element model is set up by ABAQUS for simulation analysis. The results show that the natural vibration frequencies and mode function of the prestressed CFRT simply supported beam calculated by the theoretical formulas are reliable since the relative errors of the first-order frequencies under different prestressing levels are within 6% compared with the finite element results. Further analysis of the prestressing parameters is carried out using the theoretical formulas, in which factors such as the prestressing level, eccentricity of tendons, and tensile stiffness of prestressed tendons have different influences on the natural vibration frequencies. Finally, it provides a theoretical basis for the dynamic design of the prestressed CFRT beams.

Key words: prestress, concrete-filled rectangular steel tube (CFRT), vibration, finite element analysis

摘要： 基于D'Alembert原理推导了新型部分填充混凝土的预应力矩形钢管混凝土梁动力学控制方程，并求解得到了预应力矩形钢管混凝土简支梁动力特性的解析结果。同时应用ABAQUS软件建立有限元模型进行了仿真分析。结果表明，理论公式计算的预应力矩形钢管混凝土简支梁的自振频率和振型是可靠的，不同的预应力水平下一阶频率较有限元结果相对误差均在6%以内。进一步采用理论公式进行了预应力参数分析，其中预应力水平、布筋偏心距和预应力筋抗拉刚度等因素对自振频率均有不同程度的影响，为预应力矩形钢管混凝土梁动力设计提供了理论依据。

关键词: 预应力，钢管混凝土，振动，有限元分析