Development of automatic measuring system of ultrasonic attenuation using spectrum analysis

频谱分析超声衰减自动测量系统的研制

基本信息

批准号：
63850022
负责人：
OKAMURA Hiroyuki
金额：
$ 5.38万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63850022/
关键词：
Ultrasonic Attenuation Ultrasonic Testing Non Destructive Testing Fatigue Creep Estimation of Remaining Life Spectrum Analysis Automatic Measuring System 超音波測定クリープ

项目摘要

The life extension of high temperature plants is strongly expected recently, so that the accurate remaining life assessment of them has come to be an important problem. This report presents a new non-destructive evaluation technique using ultrasonic waves for the evaluation of aging deterioration damage ( caused by creep and high temperature fatigue ) of high temperature components. In previous works, ultrasonic attenuation is evaluated from the 1st and 2nd peak values of pulse-echo ultrasonic wave. However the attenuation values evaluated by this method may have some error, because those values are greatly affected by the super-imposed noise. In the present work, two new algorithms for the improvement of measuring accuracy of ultrasonic attenuation using spectrum analysis has been developed. One is the method that evaluates the attenuation values from envelope curve of original ultrasonic waves, the other is that evaluates the attenuation values by calculating the system function of specimen from the 1st and 2nd echoes. Several ultrasonic waves obtained from Monte Carlo simulation and degraded specimen are analyzed by using, both the proposed methods and the conventional method. It is shown through the comparison that the proposed methods enable us to measure ultrasonic attenuation more accurately than before, and that the attenuation values tend to increase as decreasing of the remaining life. It is also clarified that the attenuation values is effective as non- destructive evaluation parameter of creep and high temperature fatigue. The developed algorithms are installed on the measuring system which consists of a personal computer, ultrasonic apparatus, and digital storage oscilloscope. In addition the analysis time is very much shortened by incorporating FFT-analyzer in this system. Finally, all of procedures of instrumentation and analysis can be automated fully, and it will enable us to apply the above ultrasonic method to real structures.

高温植物的寿命延长最近是很强烈的，因此对它们的准确剩余寿命评估已经成为一个重要的问题。本报告使用超声波波介绍了一种新的非破坏性评估技术，用于评估高温成分的衰老劣化损伤（由蠕变和高温疲劳引起）。在先前的作品中，从脉冲 - 回波超声波的第一和第二峰值评估了超声波衰减。但是，通过此方法评估的衰减值可能会有一些错误，因为这些值受到超级噪声的极大影响。在目前的工作中，已经开发了两种新的算法，用于提高使用频谱分析的超声波衰减精度。一种是从原始超声波的包膜曲线中评估衰减值的方法，另一种是通过计算从第一和第二回声的样品的系统功能来评估衰减值的方法。通过使用所提出的方法和常规方法分析了从蒙特卡洛模拟和降解样本获得的几种超声波。通过比较表明，提出的方法使我们能够比以前更准确地测量超声衰减，并且随着其余寿命的降低，衰减值往往会增加。还可以澄清的是，衰减值作为蠕变和高温疲劳的非破坏性评估参数有效。开发的算法安装在测量系统上，该算法由个人计算机，超声波设备和数字存储示波器组成。此外，通过将FFT-Analyzer掺入该系统中，分析时间大大缩短了。最后，所有仪器和分析过程都可以完全自动化，这将使我们能够将上述超声波方法应用于真实结构。