预应力对体外预应力简支钢梁自振频率的影响

Effect of prestress force on natural frequency of external prestressed simply supported steel beam

利用有限元方法建立了体外预应力简支钢梁的有限元模型,对不同预应力值及预应力筋不同偏心距布置条件下简支钢梁的自振频率进行动力仿真分析。通过仿真结果分析预应力大小对自振频率的影响规律及影响程度,最后给出了预应力值与桥梁自振频率的定量关系,为开展预应力简支梁中有效预应力的识别提供了一定的理论支撑。

The finite element method was used to build a finite element model for the external prestressed simply supported steel beam to simulate dynamically the natural frequencies of the beam under different prestress forces and different prestressed reinforcement eccentricity arrangements. Based on the results, the behavior and the extent of the effect of the prestress force on the natural frequencies were analyzed and the quantitative relations between the prestress force and the natural frequencies of the bridge were obtained, giving a theoretical support for the idcntitication of the effective prestress force in the prestressed simply supported beams.