scholarly journals Signal Separation in Ultrasonic Non-Destructive Testing

10.14311/992 ◽  
2007 ◽  
Vol 47 (6) ◽  
Author(s):  
V. Matz ◽  
M. Kreidl ◽  
R. Šmíd
Keyword(s):  
Noise Reduction ◽  
Wiener Filter ◽  
Signal Separation ◽  
Material Structure ◽  
Discrete Wavelet ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ultrasonic Signals ◽  
Signal Processing Methods ◽  
Non Destructive

In ultrasonic non-destructive testing the signals characterizing the material structure are commonly evaluated. The sensitivity and resolution of ultrasonic systems is limited by the backscattering and electronic noise level commonly contained in the acquired ultrasonic signals. For this reason, it is very important to use appropriate advanced signal processing methods for noise reduction and signal separation. This paper compares algorithms used for efficient noise reduction in ultrasonic signals in A-scan. Algorithms based on the discrete wavelet transform and the Wiener filter are considered. Part of this paper analyses and applies blind source separation, which has never been used in practical ultrasonic non-destructive testing. All proposed methods are evaluated on both simulated and acquired ultrasonic signals. 

scholarly journals Defect Estimation in Non-Destructive Testing of Composites by Ultrasonic Guided Waves and Image Processing

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 315 ◽  
Author(s):  
Kumar Anubhav Tiwari ◽  
Renaldas Raisutis ◽  
Olgirdas Tumsys ◽  
Armantas Ostreika ◽  
Kestutis Jankauskas ◽  
...  
Keyword(s):  
Image Processing ◽  
Composite Structures ◽  
Guided Waves ◽  
Low Frequency ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Discrete Wavelet ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Non Destructive

The estimation of the size and location of defects in multi-layered composite structures by ultrasonic non-destructive testing using guided waves has attracted the attention of researchers for the last few decades. Although extensive signal processing techniques are available, there are only a few studies available based on image processing of the ultrasonic B-scan image to extract the size and location of defects via the process of ultrasonic non-destructive testing. This work presents an image processing technique for ultrasonic B-scan images to improve the estimation of the location and size of disbond-type defects in glass fiber-reinforced plastic materials with 25-mm and 51-mm diameters. The sample is a segment of a wind turbine blade with a variable thickness ranging from 3 to 24 mm. The experiment is performed by using a low-frequency ultrasonic system and a pair of contact-type piezoceramic transducers kept apart by a 50-mm distance and embedded on a moving mechanical panel. The B-scan image acquired by the ultrasonic pitch-catch technique is denoised by utilizing features of two-dimensional discrete wavelet transform. Thereafter, the normalized pixel densities are compared along the scanned distance on the region of interest of the image, and a −3 dB threshold is applied to the locations and sizes the defects in the spatial domain.

scholarly journals The De-Noising of Sonic Echo Test Data through Wavelet Transform Reconstruction

1999 ◽  
Vol 6 (5-6) ◽  
pp. 267-272 ◽  
Author(s):  
J.N. Watson ◽  
P.S. Addison ◽  
A. Sibbald
Keyword(s):  
Wavelet Transform ◽  
Test Data ◽  
Discrete Wavelet ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Transform Method ◽  
Mexican Hat Wavelet ◽  
Mexican Hat ◽  
Non Destructive

This paper presents the results of feasibility study into the application of the wavelet transform signal processing method to sonic based non-destructive testing techniques. Finite element generated data from cast in situ foundation piles were collated and processed using both continuous and discrete wavelet transform techniques. Results were compared with conventional Fourier based methods. The discrete Daubechies wavelets and the continuous Mexican hat wavelet were used and their relative merits investigated. It was found that both the continuous Mexican hat and discrete Daubechies D8 wavelets were significantly better at locating the pile toe compared than the Fourier filtered case. The wavelet transform method was then applied to field test data and found to be successful in facilitating the detection of the pile toe.

Parametric optimization of pulse-echo laser ultrasonic system for inspection of thick polymer matrix composites

2020 ◽  
Vol 19 (2) ◽  
pp. 443-453 ◽  
Author(s):  
AD Abetew ◽  
TC Truong ◽  
SC Hong ◽  
JR Lee ◽  
JB Ihn
Keyword(s):  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Laser Ultrasonic ◽  
Ultrasonic Signals ◽  
Peak Energy ◽  
Pulse Echo ◽  
Non Destructive

One of the main challenges of using laser ultrasonic techniques for non-destructive testing applications is the typically low signal-to-noise ratio of the laser ultrasonic signals. In the case of thick composite structures, this is even more problematic since composite materials have very strong sound attenuation. This article investigates the effects of laser beam size and profile to the amplitude of pulse-echo laser ultrasonic signals with the constraint that the peak energy density (fluence) must be kept constant under the thermal damage threshold of material like polymer matrix composites. Such constraint is very important for the non-destructive feature of non-destructive testing, yet in a number of the existing parameter studies of laser ultrasonics, it was not fully investigated. In this article, a series of A-scan and C-scan experiments on thick composite specimens shows that the amplitude of the direct waves and the reflected waves increases with the increase in laser beam size with constant peak energy density. This amplitude enhancement significantly improves the propagation depth, thereby optimizing the system for inspection of thick composite structures. The validity of experimental results is verified theoretically by solving the thermoelastic model of epicenter displacement using Laplace–Hankel transformation.

Multivariate non-destructive evaluation for tensile strength of steel based on neural network

2021 ◽  
Vol 63 (7) ◽  
pp. 427-435
Author(s):  
Junyang Tan ◽  
Dan Xia ◽  
Shiyun Dong ◽  
Honghao Zhu ◽  
Binshi Xu
Keyword(s):  
Tensile Strength ◽  
Magnetic Hysteresis ◽  
Barkhausen Noise ◽  
Non Destructive Testing ◽  
Magnetic Barkhausen Noise ◽  
Testing Methods ◽  
Destructive Testing ◽  
Ultrasonic Signals ◽  
Non Destructive Evaluation ◽  
Non Destructive

Tensile strength (TS) is an important mechanical property of a material. The conventional mechanical measurement method destroys the object under investigation; hence, the non-destructive evaluation of tensile strength of materials has become a research hotspot in recent years. Currently, there are some accuracy problems associated with evaluating the tensile strength of materials on the basis of single non-destructive testing (NDT) methods such as ultrasonic or electromagnetic methods. In this study, 45 steel is used as an example to study various non-destructive testing methods. First, seven different heat treatment systems are used to prepare standard specimens with different tensile strengths, which are measured by tensile tests. Second, non-destructive testing signals for each specimen are obtained as ultrasonic signals, magnetic Barkhausen noise and magnetic hysteresis signals, and the characteristic parameters of the signals are extracted. Then, single-parameter non-destructive evaluation (SNE) models of tensile strength with three different non-destructive testing methods are developed. Furthermore, a multivariate non-destructive evaluation (MNE) method based on ultrasonic signals, magnetic Barkhausen noise and magnetic hysteresis is proposed to improve the accuracy of the tensile strength measurements obtained from non-destructive testing. A deep residual network (ResNet) is used to combine the features of the three non-destructive testing parameters and an MNE model of tensile strength is developed. Moreover, a data pretreatment method based on the fuzzy mapping relationship is applied to train the MNE model successfully and enhance the stability, accuracy and reliability of the obtained results. Finally, the accuracies of the above four tensile strength evaluation models are confirmed by verification using the specimens. The results show that the MNE model has higher accuracy than the SNE models.

Assessment of Historic Structures Based on GPR, Ultrasound, and Impact-Echo Data Fusion

2013 ◽  
Vol 569-570 ◽  
pp. 1210-1217
Author(s):  
Gonzalo Safont ◽  
Addisson Salazar ◽  
Luis Vergara ◽  
Antonio Vidal ◽  
Alberto Gonzalez
Keyword(s):  
Ground Penetrating Radar ◽  
Material Structure ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Impact Echo ◽  
Feature Processing ◽  
Scale Models ◽  
Historic Structures ◽  
Ground Penetrating ◽  
Non Destructive

This paper presents a method for assessment of historic structures based on the fusion of data from ground-penetrating radar (GPR), ultrasound, and impact-echo testing. The method consists of the following steps: measuring, feature extraction, fusion, representation, and evaluation. The employed techniques for an application in scale models of historical walls are described. Thus, experimental deployment; signal feature processing; fusion operators (including order statistics digital filters); 2D non-destructive testing images, and figures of merits of the fused results are explained in detail. The deformation of different imperfections in the material structure related to the application of weight load increments applied on the wall is analyzed by using different kinds of fusion configurations.

scholarly journals Effect of the Grain Sizes on the Ultrasonic Propagation and Attenuation on Different Types of Steels Microstructure During Non-Destructive Testing

2021 ◽  
Vol 45 (4) ◽  
pp. 329-334
Author(s):  
Irida Markja ◽  
Klodian Dhoska ◽  
Dervish Elezi ◽  
Reza Moezzi ◽  
Michal Petru
Keyword(s):  
Research Work ◽  
Ultrasonic Waves ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ultrasonic Signals ◽  
Ultrasound Waves ◽  
Different Types ◽  
Shift Frequency ◽  
Ultrasonic Propagation ◽  
Non Destructive

In this paper we have proposed an experimental study of the steel grains sizes effect on the shift frequency of the ultrasonic waves being propagated in steels. Ultrasonic testing has been used in most inspection services for different materials as non-destructive testing. The novelty of our research work has been focused on the investigation of the new method for determining microstructure evolution of metals by using ultrasonic signals in conjunction with changes in grain size and hardness of steels. Furthermore, we have studied the microstructure of steel types S355, S275, Corten B and S275N. The microstructure results of steels have shown the changes that have been undergone from thermal and mechanical processes by using the attenuation of ultrasound waves during non-destructive testing.

Sign in / Sign up

Export Citation Format

Share Document