基于振动法的拉索抗弯刚度及拉力实用估算公式研究

Practical Estimation Formula of Bending Stiffness and Tension of Cables Based on Vibration Method

用振动法测拉索拉力时,不可忽略拉索抗弯刚度对中、短索测试结果的影响,但工程实践中难以确定拉索的抗弯刚度。采用曲线拟合方法,提出了由低阶频率估算拉索抗弯刚度及拉力的实用估算公式;用实用估算公式验算了被检验拉索的抗弯刚度及拉力,对比分析了实用估算公式与目前常用公式的拉力估算结果。研究表明:在拉力估算上,实用估算公式的计算精度在2%以内,与常用公式相同;在抗弯刚度估算上,当0≤ξ<210,实用估算公式计算精度在2%以内;实用估算公式对抗弯刚度和拉力的识别精度满足工程实践要求。

The influence of bending stiffness of cables on the test results of medium and short cables cannot be ignored when vibration method is used to measure the tension of cables,but it is difficult to determine the bending stiffness of cables in engineering practice.Using curve fitting method,a practical formula for estimating the bending stiffness and tension of cables from low-order frequencies was proposed.The bending stiffness and tension of the tested cables were checked by the practical estimation formula.The tension estimation results of the practical estimation formula and the commonly-used formula at present were compared and analyzed.The results show that the calculation accuracy of the practical formula is within 2%,which is the same as that of the commonly-used formula.With regard to the estimation of bending stiffness,the calculation accuracy of the practical estimation formula is less than 2%within the range of 0≤ξ<210,and the identification accuracy of the practical estimation formula for bending stiffness and tension meets the requirements of engineering practice.