磁谐振索力测试的温度敏感性及补偿方法

Temperature Sensitivity and Compensation Method of Cable Force Measurement Using Magnetic Resonance

磁谐振测索力方法是一种高灵敏度的索力检测新方法,为了减小磁谐振测索力方法的温度误差,基于磁弹效应和磁谐振现象,分析了感应电压与拉索索力和温度之间的相关性,制作了双线圈磁谐振传感器,搭建了水浴环境下的荷载-温度耦合试验系统,开展了空气和水浴环境下的对比试验以及水浴环境下的恒温变载试验和恒载变温试验。结果表明:水浴和空气环境下,传感器次级线圈感应电压增量随钢绞线拉力有相同的变化趋势,相同工况下各试件的滞回曲线灵敏度kV/F和滞回度D差异很小,最大差异百分比分别为7.1%和3.8%,这表明磁谐振测索力方法测试结果具有可靠的稳定性和可重复性;水浴环境相对空气环境差异较小,恒温变载曲线的灵敏度kV/F平均降低了7.5%,滞回度D平均提高了6.1%,表明在水浴环境下开展试验是可行和有效的;低温下感应电压随拉力的变化曲线具有较高的灵敏度和较低的滞回度,灵敏度随温度自25℃升高至80℃下降了47.8%;0℃~60℃范围,各工况升温过程与降温过程中感应电压与温度之间近似呈线性正相关,线性拟合优度大于0.96,利用0℃~60℃段降温-升温拟合曲线对温度拟合曲线对各变载工况下的试件进行温度补偿,最大误差集中在3%以内,表明可根据温度补偿曲线对磁谐振测索力方法进行温度补偿。

Magnetic resonance cable-force measurement is a novel cable-force detection method with high sensitivity.To reduce the temperature error in this method,the correlation between the induced voltage,cable force,and temperature was analyzed based on the magnetoelastic effect and magnetic resonance phenomenon.First,a double-coil magnetic resonance sensor was fabricated,and a load-temperature coupling test system was built in a water bath environment.Subsequently,a comparison test was conducted in the air and water bath environments,and a constant temperature variable load test and constant load variable temperature test were conducted in the water bath environment.The results show that for the water bath and air environments,the induced voltage increment in the magnetic resonance sensor's secondary coil has the same variation trend as the tension of the strand.Additionally,under the same working conditions,the hysteresis curve sensitivity kv/f and hysteresis D of each specimen have a small difference,and the maximum percentage differences are 7.1%and 3.8%,respectively.This shows that the proposed magnetic resonance cable-force measurement method has a reliable stability and repeatability.Compared with the air environment,the sensitivity of the constanttemperature variable load curve kv/r decreases by 7.5%on average,and the hysteresis D increases by 6.1%on average;however,the differences between the two is small,indicating that it is feasible and effective to conduct the test in a water bath environment.Moreover,the curve of the induced voltage with the tension at low temperatures has a higher sensitivity and lower hysteresis,and the sensitivity decreases by 47.8%as the temperature increases from 25 C to 80 C.In the range of o C-6o C,there is an approximate linear positive correlation between the induced voltage and temperature during the heating and cooling processes in each working condition,and the accuracy of the linear fit is higher than O.96.A temperature-fitting curve was then used to compensate for the temperature of the specimen under different load conditions,where the maximum eror is within 3%.Therefore,temperature compensation in the magnetic resonance cable-force measurement method should be performed based on the temperature compensation curve.