scholarly journals Comparison of Cooled and Uncooled IR Sensors by Means of Signal-to-Noise Ratio for NDT Diagnostics of Aerospace Grade Composites

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3381 ◽  
Author(s):  
Shakeb Deane ◽  
Nicolas P. Avdelidis ◽  
Clemente Ibarra-Castanedo ◽  
Hai Zhang ◽  
Hamed Yazdani Nezhad ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Non Destructive Testing ◽  
Signal To Noise ◽  
Destructive Testing ◽  
Ir Camera ◽  
Thermal Cameras ◽  
Aerial Vehicle ◽  
Noise Ratio ◽  
Processing Techniques ◽  
Non Destructive

This work aims to address the effectiveness and challenges of non-destructive testing (NDT) by active infrared thermography (IRT) for the inspection of aerospace-grade composite samples and seeks to compare uncooled and cooled thermal cameras using the signal-to-noise ratio (SNR) as a performance parameter. It focuses on locating impact damages and optimising the results using several signal processing techniques. The work successfully compares both types of cameras using seven different SNR definitions, to understand if a lower-resolution uncooled IR camera can achieve an acceptable NDT standard. Due to most uncooled cameras being small, lightweight, and cheap, they are more accessible to use on an unmanned aerial vehicle (UAV). The concept of using a UAV for NDT on a composite wing is explored, and the UAV is also tracked using a localisation system to observe the exact movement in millimetres and how it affects the thermal data. It was observed that an NDT UAV can access difficult areas and, therefore, can be suggested for significant reduction of time and cost.

scholarly journals Inductive Thermography as Non-Destructive Testing for Railway Rails

2021 ◽  
Vol 11 (3) ◽  
pp. 1003
Author(s):  
Christoph Tuschl ◽  
Beate Oswald-Tranta ◽  
Sven Eck
Keyword(s):  
Eddy Current ◽  
Electrical Discharge Machining ◽  
Rolling Contact ◽  
Heat Diffusion ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ir Camera ◽  
Advantages And Disadvantages ◽  
Average Crack ◽  
Non Destructive

Inductive thermography is a non-destructive testing method, whereby the specimen is slightly heated with a short heating pulse (0.1–1 s) and the temperature change on the surface is recorded with an infrared (IR) camera. Eddy current is induced by means of high frequency (HF) magnetic field in the surface ‘skin’ of the specimen. Since surface cracks disturb the eddy current distribution and the heat diffusion, they become visible in the IR images. Head checks and squats are specific types of damage in railway rails related to rolling contact fatigue (RCF). Inductive thermography can be excellently used to detect head checks and squats on rails, and the method is also applicable for characterizing individual cracks as well as crack networks. Several rail pieces with head checks, with artificial electrical discharge-machining (EDM)-cuts and with a squat defect were inspected using inductive thermography. Aiming towards rail inspection of the track, 1 m long rail pieces were inspected in two different ways: first via a ‘stop-and-go’ technique, through which their subsequent images are merged together into a panorama image, and secondly via scanning during a continuous movement of the rail. The advantages and disadvantages of both methods are compared and analyzed. Special image processing tools were developed to automatically fully characterize the rail defects (average crack angle, distance between cracks and average crack length) in the recorded IR images. Additionally, finite element simulations were used to investigate the effect of the measurement setup and of the crack parameters, in order to optimize the experiments.

A Review of Ultrasonic Application on Non-destructive Testing Method for Concrete Structure

2014 ◽  
Vol 70 (3) ◽  
Author(s):  
Nasarudin Ahmad ◽  
Ruzairi Abdul Rahim ◽  
Herlina Abdul Rahim ◽  
Mohd Hafiz Fazlul Rahiman
Keyword(s):  
Concrete Structure ◽  
High Speed ◽  
Structural Integrity ◽  
Surface Hardness ◽  
Concrete Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Surface Absorption ◽  
Processing Techniques ◽  
Non Destructive

Although the technique of using ultrasound has reached maturity by given the extent of the development of sensors, but the use of the various areas still can be explore. Many types of ultrasonic sensors are still at conventional in use especially for measurement equipment in the industry. With the advancement of signal processing techniques, high-speed computing, and the latest techniques in image formation based Non-destructive testing (NDT) methods, the usage of ultrasound in concrete NDT testing is very extensive because the technique is very simple and should not damage the concrete structure to be investigated. Many of the parameters need to be tested using ultrasound techniques to concrete can be realized. Starting with the initial process for of concrete mixing until the concrete matured to the age of century old. Various tests are available to test a variety of non-destructive of concrete completely, in which there is no damage to the concrete, through those where the concrete surface is damaged a bit, to partially destructive testing, such as core tests and insertion and pull-off test, which surface to be repaired after the test. Testing parameter features that can be evaluated using non-destructive testing and destructive testing of some rather large and include basic parameters such as density, elastic modulus and strength and surface hardness and surface absorption, and reinforcement location, size and distance from the surface. In some cases it is also possible to check the quality of the workmanship and structural integrity of the ability to detect voids, cracks and delamination. A review of NDT using ultrasound on concrete are presented in this paper to highlight the important aspect to consider when one to consider the application and development of ultrasound testing on concrete by considering ultrasound signal capturing, processing and presenting.

Ultrasound Imaging Using Multilayer Synthetic Aperture Focusing

2010 ◽  
Author(s):  
Martin H. Skjelvareid ◽  
Yngve Birkelund
Keyword(s):  
Signal To Noise Ratio ◽  
Synthetic Aperture ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Wave Velocities ◽  
Homogenous Medium ◽  
Synthetic Aperture Focusing ◽  
Original Time ◽  
Non Destructive ◽  
Test Objects

Synthetic aperture focusing techniques (SAFT) have already been studied within several fields of non-destructive testing, but so far only with a single, relatively homogenous medium. In this article, we modify the original time-domain SAFT in order to image the interior of a multilayer structure. Standard focusing techniques assume that the wave velocity is constant within the volume to be imaged. The concept of the root-mean-square (RMS) velocity is used here to modify the classical delay-and-sum algorithm to handle layers with differing wave velocities. A scheme for iteratively using this to estimate the interfaces between the layers is also presented. The proposed method is demonstrated on ultrasonic B-scans of two test objects immersed in water, and it is shown that the increased lateral resolution and signal-to-noise ratio of standard SAFT is extended to the multilayer case. The increased resolution also makes it possible to accurately estimate the interfaces between consecutive layers, as long as the preceding interfaces are relatively smooth.

A Study on Corrosion Defect Evaluation of Painted Metal by Using Nondestructive Tests

2008 ◽  
Vol 47-50 ◽  
pp. 1071-1075
Author(s):  
Kyung Seok Song ◽  
Myung Seok Ko ◽  
Jae Yeol Kim
Keyword(s):  
Detection System ◽  
Surface Condition ◽  
Economic Loss ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ir Camera ◽  
Nondestructive Tests ◽  
Coated Metal ◽  
Related Defect ◽  
Non Destructive

Importance on the detection of corrosion-related defect is undeniable from the fact that it can prevent significant economic loss and enhanced safety in mechanical equipments, pipes, ships, bridges, and other applications. Conventionally researched measurement methods for defect and thinning from corrosion are acoustic emission, EMAT using ultrasound, laser induced ultrasound, etc. However, these non-destructive testing methods have the shortcoming of accessibility to on-site. For instance, EMAT should be close to several millimeters to generate magnetic field in structure. For laser application, it can be applied to remote non-destructive testing, but some defect might not be possible to be detected by the surface condition of structure. In this study, infrared thermography camera is utilized to determine the degree of corrosion on paint-coated metal. In addition, fundamental researches to develop corrosion detection system for on-site metallic structure are conducted to provide the applicability of IR camera and possibility of thermal analysis method.

Aircraft non-destructive testing using an unmanned aerial vehicle (Conference Presentation)

2020 ◽  
Author(s):  
Shakeb Deane ◽  
Nicolas P. Avdelidis ◽  
Clemente Ibarra-Castanedo ◽  
Hamed Yazdani-Nezhad ◽  
Tim Mackley ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Aerial Vehicle ◽  
Non Destructive

scholarly journals A Versatile Illumination System for Real-Time Terahertz Imaging

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3993
Author(s):  
Jean-Baptiste Perraud ◽  
Adrien Chopard ◽  
Jean-Paul Guillet ◽  
Pierre Gellie ◽  
Antoine Vuillot ◽  
...  
Keyword(s):  
Real Time ◽  
Signal To Noise Ratio ◽  
Beam Steering ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Full Field ◽  
Illumination System ◽  
Optimized Distribution ◽  
Non Destructive ◽  
Field Imaging

Terahertz technologies are attracting strong interest from high-end industrial fields, and particularly for non-destructive-testing purposes. Currently lacking compactness, integrability as well as adaptability for those implementations, the development and commercialisation of more efficient sources and detectors progressively ensure the transition toward applicative implementations, especially for real-time full-field imaging. In this work, a flexible illumination system, based on fast beam steering has been developed and characterized. Its primary goal is to suppress interferences induced by the coherence length of certain terahertz sources, spoiling terahertz images. The second goal is to ensure an enhanced signal-to-noise ratio on the detector side by the full use and optimized distribution of the available power. This system provides a homogeneous and adjustable illumination through a simplified setup to guarantee optimum real-time imaging capabilities, tailored to the sample under inspection. Working toward industrial implementations, different illumination process are conveniently assessed as a result of the versatility of this method.

Integrated processing techniques to low signal-to-noise ratio OBC dual-sensor seismic data

2015 ◽  
Author(s):  
Baoqing Zhang* ◽  
Huawei Zhou ◽  
Zaiyu Ding ◽  
Ran Li ◽  
Zhaoquan He ◽  
...  
Keyword(s):  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Dual Sensor ◽  
Integrated Processing ◽  
Noise Ratio ◽  
Processing Techniques
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