Nondestructive Evaluation Capability Research Articles

AI-Enabled Robotic NDE for Structural Damage Assessment and Repair

The aim of this paper is to develop the concept and a prototype of an intelligent mobile robotic platform that is integrated with nondestructive evaluation (NDE) capabilities for autonomous live inspection and repair. In many industrial environments, such as the application of power plant boiler inspection, human inspectors often have to perform hazardous and challenging tasks. There is a significant chance of injury, considering the confined spaces and limited visibility of the inspection environment and hazards such as pressurization and improper water levels. In order to provide a solution to eliminate these dangers, the concept of a new robotic system was developed and prototyped that is capable of autonomously sweeping the region to be inspected. The robot design contains systematic integration of components from robotics, NDE, and artificial intelligence (AI). A magnetic track system is used to navigate over the vertical steel structures required for examination. While moving across the inspection area, the robot uses an NDE sensor to acquire data for inspection and repair. This paper presents a design of a portable NDE scanning system based on eddy current array probes, which can be customized and installed on various mobile robot platforms. Machine learning methods are applied for semantic segmentation that will simultaneously localize and recognize defects without the need of human intervention. Experiments were conducted that show the NDE and repair capabilities of the system. Improvements in human safety and structural damage prevention, as well as lowering the overall costs of maintenance, are possible through the implementation of this robotic NDE system.

Fusion of multi-view ultrasonic data for increased detection performance in non-destructive evaluation.

State-of-the-art ultrasonic non-destructive evaluation (NDE) uses an array to rapidly generate multiple, information-rich views at each test position on a safety-critical component. However, the information for detecting potential defects is dispersed across views, and a typical inspection may involve thousands of test positions. Interpretation requires painstaking analysis by a skilled operator. In this paper, various methods for fusing multi-view data are developed. Compared with any one single view, all methods are shown to yield significant performance gains, which may be related to the general and edge cases for NDE. In the general case, a defect is clearly detectable in at least one individual view, but the view(s) depends on the defect location and orientation. Here, the performance gain from data fusion is mainly the result of the selective use of information from the most appropriate view(s) and fusion provides a means to substantially reduce operator burden. The edge cases are defects that cannot be reliably detected in any one individual view without false alarms. Here, certain fusion methods are shown to enable detection with reduced false alarms. In this context, fusion allows NDE capability to be extended with potential implications for the design and operation of engineering assets.

Nondestructive Evaluation – A Critical Part of Structural Integrity

The structural integrity of modern structures and systems depend on the use and capabilities of nondestructive evaluation (NDE) for quality assurance in production; condition monitoring and repair assessments in service; risk analysis; and service/lifetime retirement. NDE is an ancient technology that has been applied, in many forms, since the beginning of time. The development and application of fracture mechanics was a revolution in design and structures management; imposed new and demanding requirements for NDE applications; and incorporated NDE as a critical part of design, production and management of critical structures and systems. New NDE requirements included quantification of capabilities and supporting considerations and technologies for development, validation, application and assessment of NDE capabilities and practices. NDE methods provide indirect measures / assessments of a desired property or condition and involve complex integration of parameters to produce the desired end result. Assessments of the capability and reliability of NDE procedures is continually evolving as an NDE engineering technology that is generally described in terms of a “probability of detection” (POD) metric. This paper summarizes the origin of the POD metric; various approaches to addressing POD requirements; considerations in NDE engineering; and suggested paths forward.

Development of a neutron tomography system using a low flux reactor

Abstract A neutron tomography instrument was designed and developed at the Royal Military College (RMC) of Canada with Queen's University to enhance these institutions' non-destructive evaluation capabilities. The neutron imaging system was built around a Safe Low-Power C(K)ritical Experiment (SLOWPOKE-2) nuclear research reactor. The low power and physical geometry of the reactor required that a novel design be developed to facilitate tomography. A unique rotisserie style rotary stage and clamping apparatus was developed. Furthermore, the low flux at the image plane (3×104 n cm−2 s−1), necessitated that the image acquisition and reconstruction processes be optimized. Tomographs of numerous samples were obtained using the new tomography instrument at RMC.

Composite non-destructive evaluation system for probability of detection assessment

In non-destructive evaluation (NDE) studies, the probability of detection (POD) curve is an important performance metric for an NDE system. POD curve estimation and NDE capability assessment are based on the flaws detected and the flaws missed. In order to get the information of undetected flaws, fabricated artificial flaws are often used which provide complete information of defects in most of laboratory demonstrations. However, this practice is too expensive and impractical to use in the field environment. In this study, a combination of several additional NDE inspection systems, called composite NDE system, is proposed to assist the POD evaluation based on field inspection. A simulation model is built to evaluate the effectiveness of the composite NDE system. The simulation result of this approach is verified and compared with traditional POD evaluation methods.

Non-destructive ultrasonic techniques on sequence error of carbon fiber/epoxy composite solid laminates

When propagating in the thickness direction of composite laminates, shear ultrasonic waves are particularly sensitive to layup sequence in the cured CF/Epoxy composite laminates manufactured from unidirectional prepregs and are interacting with the polarization direction of propagating through its thickness. The strength and stiffness in laminates often are attributable to the specific fiber orientation and layup sequence. So the layup orientation greatly influences its properties in a composite laminate. There is a good correlation between the model and the non-destructive ultrasonic technique developed to inspect the sequence error of cured symmetric layups of the laminates. The physical model is based on the decomposition and recombination of shear polarization. Non-destructive evaluation capabilities are highly desirable for reusing unidirectional prepreg sheets.

Phase transition of copper(II) phthalocyanine thin films characterized by a near-field microwave microprobe

Metal phthalocyanine is one of the promising organic compounds due to the possibility of applications in electrooptical devices, photoconducting agents, photovoltaic cell elements, nonlinear optics, electrocatalysis, and other photoelectronic devices. Several metal substituted phthalocyanines have been widely investigated. Among the metal substituted phthalocyanines, copper (II) phthalocyanine (Cu-Pc) has been found to have superior properties. Cu-Pc is a p-type semiconductor and mobility changes could be achieved by employing controlled substrate heating temperature during deposition. The crystal phase and the grain orientation of Cu-Pc depend on the heat-treatment temperatures and substrate heating conditions [1]. In order to better characterize the electrical properties of theαand the β-phase of Cu-Pc thin films, we take advantage of the nondestructive evaluation capabilities of a near-field microwave microprobe (NFMM) [2]. NFMM techniques with high sensitivity have been developed for the microwaveand millimeter-wave ranges. An important ability of the NFMM is nondestructive and contactless characterization of thin films, in particular, the characterization of electrical properties of organic thin films. Organic multilayer thin films have attracted considerable interest in regard to various display applications. Nondestructive and contactless characterization techniques are very useful for these applications. NSMM technique, which directly measures the physical properties such as surface resistance of organic thin films shows practical promise. To study the phase transition of Cu-Pc thin films, wemeasured the surface resistance using a NFMM by measuring the microwave reflection coefficient S11. The crystal structure of Cu-Pc thin films transformed from the α-phase of the orthorhombic crystal to the thermally stable β-phase of themonoclinic crystal as the substrate heating temperatures increased. The surface resistance depended on the crystal structures of the Cu-Pc thin films. As the phase changed from the α-phase to the β-phase, the surface resistance of the Cu-Pc thin films decreased.

Quantified nondestructive evaluation capability; A major element in engine structural integrity programs

Quantification de l'aptitude au controle non destructif. Presentation de la methode de conception, des composants de moteurs d'avions de la norme americaine MIL-STD-1783. Un composant doit pouvoir tolerer une fissure dont les dimensions sont celles de la plus petite fissure decelable par un essai non destructif

Solid Mechanics Research for Quantitative Non-Destructive Evaluation

Abstract : Non-destructive evaluation (NDE) procedures play an important role in materials processing, as well as in subsequent material testing, product design, analysis of service life expectancy, manufacturing, and quality control of manufactured products. They are also essential to on line monitoring of the integrity of structural elements and complex systems. Rational accept and reject criteria should be based on NDE tests. Critical safety, efficiency and operational features of large-scale structures depend on adequate NDE capabilities. Acoustic Emission, Dynamic Fracture, Materials and Transducer Characterization, Failure Mechanisms and Processes in Composites using Acoustic Emission, Flaw Characterization by Ultrasonic Scattering Methods, Experimental Research on Ultrasonic Scattering from Flaws, Elastic Wave Interactions with Partially Contacting Surfaces: Application to Fatigue Crack Characterization, Ultrasonic Nondestructive Evaluation, Microstructure, and Fracture Toughness Interrelations, Low Frequency Acoustic Microscopy, Ultrasonic NDE of Composites as Inhomogeneous Media, Non destructive Characterization of Damage in Graphite Epoxy Laminates.

Nondestructive evaluation and energy technology: a workshop summary

The findings of a recent Workshop on Nondestructive Evaluation (NDE) are summarized. One purpose of the Workshop was to recommend basic research programs to develop the scientific base for improvements in NDE capabilities. The research programs recommended span such disciplines as physics, mathematics, materials science, mechanical engineering and electrical engineering and include research with such objectives as developing quantitative relationships for the interaction of various types of penetrating radiation (elastic and electromagnetic waves, X-rays, gamma rays, neutron etc.) with important material structures (flaws, welds, cladding, grain structure etc.) and for the influence of these structures on material performance (fracture, fatigue etc.). Additional research recommendations include examining the inverse problem in general and acoustic emission in particular, promoting advanced instrumentation development for improved signal detection and discrimination, for in situ and real-time operation and for generation of more easily interpretable data forms (e.g. imaging and tomographic methods), and consciously promoting research on relevant promising new phenomena and methods. An important facet of the research recommendations is the affirmation of the interdisciplinary character of NDE and the importance of interdisciplinary approaches to the research.