高能脉冲磁弹仪器研制及其索力表征实验研究

Development of High Energy Pulsed Magnetoelastic Instrument and Experimental Study on Cable Force Characterization

针对在役桥梁钢索的索力检测需求,基于磁弹效应检测机理,首先,设计了便携式脉冲磁弹索力检测仪器,其可输出0~600 V电压可调、电流峰值高达60 A的高能尖峰脉冲信号,实现了对不同直径钢索的充分磁化,仪器主要包括上位机(含软件)、具有反馈控制的脉冲磁弹仪下位机和基于多芯线缆的改进磁弹传感器;其次,对公称直径17.8 mm的七芯钢绞线进行加载和卸载索力检测实验,实现了钢绞线的饱和磁化,磁弹传感器绕制效率是传统方法的8倍,分析了传统索力表征参量与索力之间的线性相关性;最后,在此基础上,提出一种索力表征参量--饱和磁导率μs,其线性拟合优度大于95%,且灵敏度(0.05)高于传统参量。通过对索力表征误差分析,该参量相较于传统参量在索力表征方面显示出较低的预测误差(3.7%)和迟滞误差(±1.54%)。该研究提出的参量可为脉冲磁弹法检测索力提供新的表征方法。

Based on the mechanism of magnetoelastic effect,a high energy pulsed magnetoelastic cable force detector was developed to meet the demand for cable force detection of bridges in service.First,a portable pulsed magnetoelastic cable force detection instrument powered by solar energy was designed.The instrument could output high energy spike pulse signals with adjustable voltage in the range of 0-600 V and current peak up to 60 A,to realize full magnetization of cables with different diameters.The instrument mainly included an upper computer(including software),a lower computer of the pulse magnetoelastic instrument with feedback control and an improved magnetoelastic sensor based on multi-core cables.Besides,the loading and unloading tension tests of the 7-core steel strand with a nominal diameter of 17.8 mm were carried out,the saturation magnetization of the strand was realized,the winding efficiency of the magnetoelastic sensor was increased by 8 times compared with the traditional method,and the linear correlation between the traditional cable force characterization parameters and the tension was analyzed.Finally,a parametric,saturated permeability,μs of cable force characterization was proposed,which had linear goodness of fit greater than 95%and higher sensitivity(0.05)compared with traditional parameters.By analyzing the tension characterization errors,the parameter shows lower prediction error(3.7%)and hysteresis error(±1.54%)than traditional parameters.The parameter proposed in this paper can provide a characterization method for detecting tension by the pulsed magnetoelastic method.