Design of an Automatic Defect Identification Method Based ECPT for Pneumatic Pressure Equipment

In this paper, in order to achieve automatic defect identification for pneumatic pressure equipment, an improved feature extraction algorithm eddy current pulsed thermography (ECPT) is presented. The presented feature extraction algorithm contains four elements: data block selection; variable step search; relation value classification; and between-class distance decision function. The data block selection and variable step search are integrated to decrease the redundant computations in the automatic defect identification. The goal of the classification and between-class distance calculation is to select the typical features of thermographic sequence. The main image information can be extracted by the method precisely and efficiently. Experimental results are provided to demonstrate the capabilities and benefits (i.e., reducing the processing time) of the proposed algorithm in automatic defect identification

Nondestructive testing of metals and composite materials using ultrasound thermography : comparison with pulse-echo ultrasonics

La thermographie stimulée par ultrasons (TU) est une méthode de contrôle non destructif qui a été inventée en 1979 mais qui a s'est répandue à la fin des années 90. L'idée de cette méthode est d'exciter le matériau à inspecter avec des ondes mécaniques à des fréquences allant de 20kHz à 40kHz et d'observer ensuite leur température de surface avec une caméra infrarouge. TU est une méthode de thermographie active; les autres méthodes les plus connues sont la thermographie optique et celle stimulée par courants de Foucault. Son habilité à révéler des défauts dans des cas où les autres techniques échouent, fait d'elle une méthode pertinente ou complémentaire. L'inconvénient de la TU est que beaucoup de conditions expérimentales doivent être respectées pour obtenir des résultats adéquats incluant quelques paramètres qui doivent être bien choisis. Le but de ce projet est d'explorer les capacités, les avantages et les limites de la TU. Pour comparer la performance de la TU à celle des ultrasons conventionnels, des tests ultrasons de type C-Scan ont été réalisés pour quelques échantillons. Quatre matériaux différents avec quatre types de défauts ont été investigués afin de mieux définir les conditions optimales pour améliorer la détection des défauts. Les résultats bruts obtenus étaient traités dans chaque cas afin de mieux visualiser les contrastes thermiques causés par les discontinuités cachées

Numerical modeling of infrared thermography techniques via ANSYS

Several inspection techniques have been developed over years. Recently, infrared thermography (IRT) technology has become a widely accepted as a nondestructive inspection (NDI) technique for different fields and various applications as well. Infrared thermography stands as one of the most an attractive and a successful NDI technique that has ability to detect the object\u27s surface/subsurface defects remotely based on observing and measuring the surface\u27s emitted infrared heat radiation by using an infrared camera. The finite element modeling FEM ANSYS was successfully used for the modelling of several IRT techniques; such as Pulsed Thermography (PT) and Lock-in Thermography (LT) that can be used to detect the in-plane defects which are parallel to its surface; besides a Laser Spot Thermography (LST) technique that can be used to detect the cracks which are perpendicular to its surface. Furthermore; this thesis describes how LST method can be extended to a new technique, Laser Digital Micromirror Thermography (LDMT), based on using a digital micromirror device (DMD) that has ability to generate multi-hot spots onto the specimen\u27s surface being examined by using single laser source. In one hand, this thesis aims to show investigations about infrared thermography technology as a non-destructive inspection (IRT-NDI) by using numerical modeling methods via ANSYS. On the other hand, this thesis presents FEM ANSYS as a powerful tool allows doing several inspections, analyses, and evaluations of thermography techniques tests based on numerical modeling simulations and comparing their results to the corresponding experiments in literature experiment tests to validate these simulations and show a reasonable agreement to use ANSYS as a thermography inspection tool for future study and researches --Abstract, page iii

Numerical modeling of infrared thermography techniques via ANSYS

Several inspection techniques have been developed over years. Recently, infrared thermography (IRT) technology has become a widely accepted as a nondestructive inspection (NDI) technique for different fields and various applications as well. Infrared thermography stands as one of the most an attractive and a successful NDI technique that has ability to detect the object\u27s surface/subsurface defects remotely based on observing and measuring the surface\u27s emitted infrared heat radiation by using an infrared camera. The finite element modeling FEM ANSYS was successfully used for the modelling of several IRT techniques; such as Pulsed Thermography (PT) and Lock-in Thermography (LT) that can be used to detect the in-plane defects which are parallel to its surface; besides a Laser Spot Thermography (LST) technique that can be used to detect the cracks which are perpendicular to its surface. Furthermore; this thesis describes how LST method can be extended to a new technique, Laser Digital Micromirror Thermography (LDMT), based on using a digital micromirror device (DMD) that has ability to generate multi-hot spots onto the specimen\u27s surface being examined by using single laser source. In one hand, this thesis aims to show investigations about infrared thermography technology as a non-destructive inspection (IRT-NDI) by using numerical modeling methods via ANSYS. On the other hand, this thesis presents FEM ANSYS as a powerful tool allows doing several inspections, analyses, and evaluations of thermography techniques tests based on numerical modeling simulations and comparing their results to the corresponding experiments in literature experiment tests to validate these simulations and show a reasonable agreement to use ANSYS as a thermography inspection tool for future study and researches --Abstract, page iii

Characterization of vertical cracks using lock-in vibrothermography

214 p.Esta tesis se centra en la aplicación de la vibrotermografía lock-in para la detección y caracterización dedefectos verticales sumergidos. En esta técnica, la pieza se excita mediante ultrasonidos, que generancalor en los defectos por fricción o deformación plástica. Este calor se difunde por el material y susefectos se pueden detectar midiendo la temperatura superficial mediante una cámara infrarroja. Con el finde caracterizar defectos es necesario resolver el problema inverso, que consiste en recuperar la geometríade las fuentes de calor a partir de la distribución de temperatura superficial medida. Éste es un problemamal puesto, ya que su solución es fuertemente dependiente de pequeños errores en los datos y la inversiónes inestable. Se ha implementado un algoritmo de inversión robusto, basado en minimización pormínimos cuadrados estabilizados mediante términos de penalización basados en los funcionales deTikhonov, Total Variation y L1, capaz de reconstruir distribuciones de fuentes de calor partiendo de datosde vibrotermografía. El algoritmo se ha analizado con datos sintéticos y se ha optimizado con el fin deextender su aplicación a la caracterización del mayor rango de geometrías de fuentes de calor posible.Los resultados obtenidos se han verificado con datos experimentales obtenidos en ensayos devibrotermografía lock-in, utilizando muestras con fuentes de calor verticales calibradas. Finalmente, se hahecho uso del algoritmo de inversión para caracterizar grietas reales en una muestra soldada de Inconel718 y los resultados están en buena correlación cualitativa con los resultados del ensayo de líquidospenetrantes realizado posteriormente

Automated Fiber Placement: A Review of History, Current Technologies, and Future Paths Forward

Automated fiber placement (AFP) is a composite manufacturing technique used to fabricate complex advanced air vehicle structures that are lightweight with superior qualities. The AFP process is intricate and complex with various phases of design, process planning, manufacturing, and inspection. An understanding of each of these phases is necessary to achieve the highest possible manufacturing quality. This literature review aims to summarize the entire AFP process from the design of the structure through inspection of the manufactured part to generate an overall understanding of the lifecycle of AFP manufacturing. The review culminates with highlighting the challenges and future directions for AFP with the goal of achieving a closed loop AFP process

Proceedings of the 11th international conference on NDE in relation to structural integrity for nuclear and pressurized components

This Conference, the eleventh in a series on NDE in relation to structural integrity for nuclear and pressurized components, was held in Jeju Island, Korea, from 19th to 21st of May 2015. The scientific programme was co-produced by the European Commission’s Joint Research Centre, Institute for Energy and Transport (EC-JRC/IET). Previous conferences were held in Amsterdam in October 1998, New Orleans in May 2000, Seville in November 2001, London in December 2004, San Diego in May 2006, Budapest in October 2007, Yokohama in May 2009, Berlin in September 2010, Seattle in May 2012, and Cannes in October 2013. All were highly successful in the quality and scope of the technical programs and the number of attendees from all countries with an interest in the structural integrity of nuclear and pressurized components. The overall objectives of the Conference were to provide an up-to-date assessment of the development and application of NDE and to allow technical interchange between experts on an international basis. The Conference covered all aspects of this extremely important subject, with special regard to the links between structural integrity requirements and NDE performance. The development of improved NDE systems and methods was highlighted. Determination of NDE performance by development of qualification systems or performance demonstration, and experience of their use in practice was prominently featured.JRC.F.5-Nuclear Reactor Safety Assessmen

Proceedings of the 11th international conference on NDE in relation to structural integrity for nuclear and pressurized components

This Conference, the eleventh in a series on NDE in relation to structural integrity for nuclear and pressurized components, was held in Jeju Island, Korea, from 19th to 21st of May 2015. The scientific programme was co-produced by the European Commission’s Joint Research Centre, Institute for Energy and Transport (EC-JRC/IET). Previous conferences were held in Amsterdam in October 1998, New Orleans in May 2000, Seville in November 2001, London in December 2004, San Diego in May 2006, Budapest in October 2007, Yokohama in May 2009, Berlin in September 2010, Seattle in May 2012, and Cannes in October 2013. All were highly successful in the quality and scope of the technical programs and the number of attendees from all countries with an interest in the structural integrity of nuclear and pressurized components. The overall objectives of the Conference were to provide an up-to-date assessment of the development and application of NDE and to allow technical interchange between experts on an international basis. The Conference covered all aspects of this extremely important subject, with special regard to the links between structural integrity requirements and NDE performance. The development of improved NDE systems and methods was highlighted. Determination of NDE performance by development of qualification systems or performance demonstration, and experience of their use in practice was prominently featured.JRC.F.5-Nuclear Reactor Safety Assessmen

Acoustic and Elastic Waves: Recent Trends in Science and Engineering

The present Special Issue intends to explore new directions in the field of acoustics and ultrasonics. The interest includes, but is not limited to, the use of acoustic technology for condition monitoring of materials and structures. Topics of interest (among others): • Acoustic emission in materials and structures (without material limitation) • Innovative cases of ultrasonic inspection • Wave dispersion and waveguides • Monitoring of innovative materials • Seismic waves • Vibrations, damping and noise control • Combination of mechanical wave techniques with other types for structural health monitoring purposes. Experimental and numerical studies are welcome