Embedded-ultrasonics structural radar (EUSR) is a new concept and methodology for in situ nondestructive evaluation (NDE) and structural health monitoring (SHM) of thin-wall structures. EUSR consists of: (a) an array of piezoelectric wafer active sensors (PWAS) embedded into the structure; and (b) electronic modules for signal transmission/reception, processing, and interpretation. EUSR utilize...

In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE) of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms o...

In the first and second stage nuclear program of Department of Atomic Energy (DAE), technologies are matured for Pressurised Heavy Water Reactors (PHWRs) and Sodium-Cooled Fast Breeder Reactors (FBRs). Pre-service-Inspection (PSI), In-Service-Inspection (ISI) and Post-Irradiation-Examination (PIE) procedures are carried out for mechanical components and structures/assemblies of these reactors, ...

In the first and second stage nuclear program of Department of Atomic Energy (DAE), technologies are matured for Pressurised Heavy Water Reactors (PHWRs) and Sodium-Cooled Fast Breeder Reactors (FBRs). Pre-service-Inspection (PSI), In-Service-Inspection (ISI) and Post-Irradiation-Examination (PIE) procedures are carried out for mechanical components and structures/assemblies of these reactors, ...

Abstract: A significant challenge in nondestructive evaluation is the ability to discern signals, originating from a crack and a geometric feature in a part, that are either closely spaced or superimposed in time. An example problem is the ultrasonic inspection of aircraft holes in vertical riser structures with limited accessibility for a transducer from an external wing surface. Characteristi...

One of the basic mechanisms of radiation embrittlement of steels and welds is due to matrix damage. Embrittlement results in a raise in the ductile-to-brittle transition temperature, which is normally used as indicator of the degradation status of the material. Other methods different than mechanical tests can be used to follow embrittlement like small punch test, non-destructive measurements o...

We review stationary and mobile systems that are used for the nondestructive evaluation of room temperature objects and are based on superconducting quantum interference devices (SQUIDs). The systems are optimized for samples whose dimensions are between 10 micrometers and several meters. Stray magnetic fields from small samples (10 µm-10 cm) are studied using a SQUID microscope equipped with a...

Advanced signal processing techniques have been long introduced and widely used in structural health monitoring (SHM) and nondestructive evaluation (NDE). In our research, we applied several signal processing approaches for our embedded ultrasonic structural radar (EUSR) system to obtain improved damage detection results. The EUSR algorithm was developed to detect defects within a large area of...

This study utilizes microfocus x-ray computed tomography (CT) slice sets to model and characterize the damage locations and sizes in thermal protection system materials that underwent impact testing. ScanIP/FE software is used to visualize and process the slice sets, followed by mesh generation on the segmented volumetric rendering. Then, the local stress fields around several of the damaged re...

Prior to this work, an algorithmic and rule-based blackboard system (ARBS) had been developed over a ten-year period. ARBS benefited from a versatile rule structure and the ability to mix computational styles either as separate knowledgesources or by embedding algorithms within rules. It was a serial system – any knowledge source that was able to contribute had to wait its turn. We report here ...