Fourier Analysis of Ultrasonic TOFD Signals for Defect Detection in Austenitic Stainless Steel Welds
Fourier Analysis of Ultrasonic TOFD Signals for Defect Detection in Austenitic Stainless Steel Welds
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DOI：
10.5120/12385-8737
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
A. Praveen;K. Vijayarekha;Saju T. Abraham;B. Venkatraman
中科院分区：
文献类型：
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作者：
A. Praveen;K. Vijayarekha;Saju T. Abraham;B. Venkatraman
结构材料的无损检测是许多行业的一项重要活动。超声波无损检测就是该领域广泛使用的一种方法。脉冲回波和穿透传输是分别使用反射声能和透射声能的传统测试技术。但这些技术高度依赖于缺陷定位。飞行时间衍射 (TOFD) 是一种最新的方法，它使用衍射声能来检测缺陷，并且与材料中缺陷的方向无关。 TOFD 信号主要是来自各种来源的噪声，即仪器噪声、材料（结构）噪声、热噪声等。信号处理是评估用于检测、定位和表征缺陷的信号的重要步骤。傅里叶变换广泛应用于不同类型信号的分析和去噪。在本文中，使用傅立叶变换对从奥氏体不锈钢焊件获得的超声波 TOFD 信号进行了分析。
Non Destructive testing of structural materials is an important activity in many industries. Ultrasonic NDT is one such method widely used in this field. Pulse Echo and Through Transmission are conventional testing techniques which use reflected and transmitted sound energy respectively. But these techniques are highly dependent on defect orientation. Time of Flight Diffraction (TOFD) is a recent method which uses diffracted sound energy to detect the defects and is independent of orientation of the defects in the material. TOFD signals are dominated by noise arriving from various sources namely instrumental noise, material (structural) noise, thermal noise etc. Signal processing is an important step in the evaluation of the signals for detecting, positioning and characterizing the defects. Fourier Transform is widely used in the analysis and de-noising of signals of different kind. In this paper Ultrasonic TOFD signals obtained from Austenitic Stainless Steel weldments are analyzed using Fourier Transforms.