【摘要】 超声波测厚是管道腐蚀检测最重要的技术之一。常规的超声波检测管道壁厚的方法主要是利用超声波测厚仪定期对管道表面进行检测,它的局限性在于无法对埋地或者其他处于危险环境的管道进行在线监测,同时由于漂移的存在,在线监测的功能无法实现。此外,采用常规的波形自相关算法测厚,由于实际中波形的线性相关降低,单单考虑最大正相关系数位置作为超声波回波到达时刻,会导致测量的误差大大增加。因此,将管道模型转换为平板模型,在平板模型的基础上,提出了一种基于标准块和最大相关系数直线拟合算法的超声波测厚方法。仿真和实验的结果表明,这种厚度测量方法具有较高的精度。本文提出的这种新的超声波测厚方法,对超声波在线监测管道壁厚的指导具有较大意义。更多还原

【Abstract】 Thickness measurement of ultrasonic is one of the most important technologies in pipeline corrosion testing. Traditionally ultrasonic testing method of thickness of pipe uses ultrasonic thickness gauge to detect the surface of pipeline regularly, which means ultrasonic on-line monitoring can’t be used to the pipeline which located in ground or other dangerous environment, and owing to existence of drift, the function of on-line monitoring can’t be enabled. In using traditional ultrasonic waveform correlation algorithm, owing to decrease of linear correlation between waveforms, only considering the positive maximum correlation coefficient as arrival time of ultrasonic waveform will lead to the increase of measurement error. In this paper, we convert the pipeline model into the flat model, proposing a novel thickness measurement method of ultrasonic based on standard block and linear fitting algorithm of maximum correlation coefficient. The results of simulation and experiment indicate that this method has high precision. As a result, this novel thickness measurement method of ultrasonic has a great significance in ultrasonic on-line monitoring technology of the wall thickness of the pipeline.更多还原