摘要
为有效评估悬索桥索夹螺杆轴力的损失程度,提出一种可实现数据自诊断的索夹螺杆轴力超声识别方法。该方法对螺杆超声回波包络进行高斯建模,提取回波声时,并根据模型确定系数剔除异常信号;进行螺杆标定试验,确定标定螺杆应力系数和温度系数,得到螺杆轴力计算公式,并进行螺杆轴力识别。结果表明:回波中心频率为3.5~4.0 MHz时高斯回波包络模型的稳定性和可靠度较好,可将高斯回波包络模型确定系数小于0.9的实测信号作为异常信号进行剔除,实现实测数据质量的自诊断;螺杆轴力与声时差线性关系明显;基于高斯回波包络模型可实现索夹螺杆轴力自动识别与实测数据质量自诊断,轴力识别误差均在1.1%以内。
An ultrasonic method to identify axial forces of cable clamp bolts that can realize fault self-diagnosis is proposed,aiming to effectively evaluate the loss of axial forces of cable clamp bolts in suspension bridge.The Gaussian model of ultrasonic echo envelop of bolt was established to extract echo time,and the abnormal signals were eliminated using the coefficients of determination gained from the model.The bolt calibration test was conducted to determine the stress and temperature coefficients of the calibrated bolts,then,the calculation formula of bolt axial force was established and the axial forces of bolts were identified.The results indicate that the stability and reliability of Gaussian echo envelop model are sound when the central frequency of echoes is between 3.5 and 4.0 MHz.The measured signals related to the coefficients of determination of Gaussian echo envelop model that are less than 0.9 can be taken as abnormal signals for elimination,to realize the self-diagnosis of the quality of the measured data.The linear relationship between the axial force of bolt and acoustic time difference is significant.The ultrasonic identification method based on Gaussian echo envelop model can automatically identify the axial forces of cable clamp bolts and realize the self-diagnosis of measured data,and the axial force identification errors are all less than 1.1%.
作者
陈鑫
朱劲松
叶仲韬
伊建军
CHEN Xin;ZHU Jin-song;YE Zhong-tao;YI Jian-jun(School of Civil Engineering,Tianjin University,Tianjin 300072,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2021年第3期56-61,共6页
Bridge Construction
基金
国家自然科学基金项目(52078333)
天津市交通运输科技发展计划项目(G2018-29)。
关键词
悬索桥
索夹
螺杆
轴力识别
声弹性理论
超声回波包络
suspension bridge
cable clamp
bolt
axial force identification
acoustoelasticity theory
ultrasonic echo envelop
