由基频计算拉索拉力的实用公式

振动法测索力广泛应用于索结构的施工控制、状态评估和健康监测,其基本原理是基于弦振动理论。弦理论忽略了索的垂度和抗弯刚度的非线性影响,在实际应用中有时会带来不可接受的误差。采用能量法和曲线拟合方法,建立了分别考虑索垂度和抗弯刚度影响,由基频计算索力的实用公式。对公式的适用范围进行了讨论,并与现有解的结果进行了比较,表明本文公式可满足精度要求。

PRACTICAL FORMULAS TO DETERMINE CABLE TENSION BY USING CABLE FUNDAMENTAL FREQUENCY

The cable tension plays an important role in the construction control,assessment and long-term monitoring of cable-supported structures.The engineering implementation of a vibration-based cable tension evaluation is mostly carried out based on the simple taut string theory.However,the simple theory may cause unacceptable errors in many applications since the cable sag and bending stiffness are ignored.Based on the energy theory and curve fitting,practical formulas are proposed,in which the cable tension can be easily estimated by using the measured fundamental frequency and the cable sag as well as bending stiffness effects are included.The applicability of the proposed practical formulas is verified by comparison of the results with those reported in the literature.