为提高带减震器吊杆索力的识别精度,建立了一种新的吊杆索力识别方法。依据吊杆的力学行为,建立了带减震器吊杆的运动微分方程,明确了减震器刚度、吊杆索力及其振动频率间的复杂关系;建立并求解了带减震器吊杆的张拉有限元模型,获得不同减震器参数下吊杆频率、索力的计算结果,并绘制索力一频率一刚度的三维关系曲面,以实测索力和频率识别吊杆的减震器刚度,基于牛顿插值法得到该刚度下吊杆索力计算公式,据此建立带减震器吊杆索力识别的实用方法。以某180m提篮式系杆拱桥吊杆索力识别为例,对所提方法进行验证。结果表明:该方法能有效地识别各施工阶段的吊杆索力,吊杆识别相对误差均小于10%,满足实际工程的需求,该方法可用于类似的实际工程中。
To improve the accuracy of tension identification for suspender with damper, a novel method was proposed to identify the tension of suspender with damper. The motion differential equation of suspender with damper was established in light of the mechanical behavior of suspender, and the complex relations among the damper stiffness, suspender tension and its vibration frequency were determined. Tension finite element model of suspender with damper was established and calculated to obtain the corresponding analytical results of natural frequency and tension for the suspender with damper under different damper parameters. 3D relation surface of tension-frequency-stiffness for suspender was plotted out to measure tension and frequency of suspender to identify the damper stiffness. The calculated formula of suspender tension was achieved with the aid of Newton interpolation method, based on which practical tension identification method of suspender with damper was achieved. The suspender tension identification of a certain 180 m basket bowstring arch bridge was considered as a case study to verify the proposed method. The results show that the suspender tensions during each period of construction are identified effectively by the proposed method with good accuracy, and the relative error is less than 10%, which satisfies the need of actual project. The proposed method can be adopted in real construction.