Lynntech is seeking to develop real-time realistic nondestructive evaluation (NDE) and structural health monitoring (SHM) physics-based simulations, and automated data reduction/analysis methods, for large datasets. Recently, computational efficient Neural Network based simulations have demonstrated the possibility to synthesize data with an orders-of-magnitude increase in speed compared to standard computational techniques [1,2]. In this contribution, we report our initial experimental results for our Generative Adversarial Network for Realistic Physics Simulations, or GAN4RPS.
In sonic infrared (SonicIR) imaging, heat is generated in defect areas during the sonic pulse; the heat appears bright in SonicIR images as the indication of a defect. However, in practical applications of SonicIR, there are lots of disturbing bright areas in infrared images, such as heat reflection and paint problem. When crack size is small, the generated heat appears not bright enough to be recognizable. Based on heat diffusion properties in the one-dimensional temporal and two-dimensional spatial domain, a method is developed to automatically recognize defect signals from SonicIR image sequences. The algorithm is verified with the SonicIR image sequences of 100 metal plates which may have different thickness, materials, or crack sizes.
In this paper, we present our progress in the CAREER project "Investigation of Hybrid Acoustic-Infrared NDE Imaging
Mechanisms" supported by NSF Civil, Mechanical & Manufacturing Innovation Division, Sensors & Sensing Systems
program directed by Dr. Shih-Chi Liu. The project ended in September, 2009. During the project, the PIs and her
graduate students had investigated on several aspects of the innovative Sonic Infrared Imaging technology. Sonic
Infrared Imaging is a novel technique which implements the concept of combining infrared (IR) sensing and imaging
with pulsed (typically a fraction of a second) sonic/ultrasonic excitation. This technique has significant advantages over
traditional NDE techniques as an effective, fast, and wide-area NDE method. The PI has studied the fundamental issues
related to this technology, such as the non-linear vibration behavior induced in the target materials and structures
through both experimental study and theoretical calculation.
In this paper, we present our progress on developing Sonic Infrared (IR) Imaging for structural health monitoring on
steel structures. Sonic IR imaging is a fast, wide-area novel imaging NDE/SHM technique. Ultrasonic excitation was
used to stimulate heating in defects, combining with Infrared Imaging to identify defects in structures. The whole
process takes only about a second. We have been working on some steel specimens used in some typical steel
structures. Actual heating patterns are extracted from the IR images and the actual temperature changes are mapped out.
Theoretical computing is also carried out to calculate the heating pattern in the specimens with the experimental results
as benchmarks.
We have presented our preliminary results on studying the effect of two different coupling materials in Sonic Infrared (IR) Imaging, which is a hybrid ultrasonic/infrared NDE technology and can detect defects in materials and structures by detecting the changes of IR radiation of defective objects through sensors during an ultrasound excitation pulse (can be a fraction of a second), in the Smart Structures and NDE in San Diego in March 2007. Those two coupling materials produced different results in the sense of producing different IR signal levels. We have been further investigating the non-linear phenomena of different coupling materials in Sonic IR Imaging because this non-linear effect appears to play a very important role in Sonic IR Imaging technology. We focus our study on the effect of the level of coupling mechanical energy from the ultrasound transducer to the target, and the level of infrared signals produced around the defects. We present our results from those aspects in this paper.
Sonic infrared (IR) Imaging employs a short ultrasonic pulse excitation and Infrared Imaging to detect defects in
materials and structures. The ultrasound pulse, typically a fraction of a second, causes heating in the defects, which
results in the change of IR radiation from the target. This change can be detected by infrared sensors, thus, defects can
be identified. One key objective in developing this technology is to optimize the IR signal with minimum ultrasound
excitation energy being applied to the target. We have learned that the ultrasonic frequency, coupling medium between
the ultrasonic transducer and the target, the pressure from the transducer to the target, the characteristics of the target
itself, etc. are all factors that affect the IR signals. In a previous paper at this conference, we presented the thermal
energy computing tools developed for analyzing IR data. In this paper, we present the results of our study on the effect
of different coupling materials on IR signal levels for different types of materials.
Sensing technology and sensor development have received increased attention in the recent years, and a number of types
of sensors have been developed for various applications for materials and structures. In this paper, we will discuss the
concept of combining sensing of global vibration and local infrared imaging techniques. The global vibration-based
techniques determine the health condition of structures by the changes in their dynamic properties or responses to
external disturbs or excitations. Infrared Imaging is introduced here to detect local defects or problems so that to provide
more direct and accurate assessment about the severity and extent of the damage. The progress on developing a hybrid
structural health monitoring system is presented through the results on both the global sensing algorithm study and local
infrared imaging investigation on a steel C channel.
Sonic IR Imaging is a novel NDE technique, which combines a short ultrasonic pulse excitation and infrared imaging to detect defects in materials and structures. The ultrasound pulse, typically a fraction of a second long, causes heating in the defects, which results in the change of IR radiation from the target. This change can be detected by infrared sensors, and thus, defects can be identified. One key objective in developing this technology is to maximize the IR signal so that the probability of detection (POD) of defects is optimized. From our work, we learned that the ultrasonic frequency, coupling medium between the ultrasonic transducer and the target, the pressure from the transducer on the target, the characteristics of the target itself, etc. are all factors that affect the IR signals. In addition, different IR sensors have different responses for the same IR radiation. To develop Sonic IR Imaging technology, it is important to study the relationship between the IR signal and the input acoustic energy for different system configurations. In this paper, we'll describe the thermal energy computing tools developed for analyzing data from different sets of parameters in Sonic IR Imaging.
We describe Sonic Infrared Imaging NDE for materials and structures. In this imaging technique, a short ultrasonic pulse is applied to the structure/material to cause heating of the defects, while an infrared camera images the time evolution of the heating effect to identify the defective areas in the target. The heating effect is astonishing. In this paper, we'll include our study of Sonic IR imaging NDE on aircraft structure specimens, automotive specimens, etc. for metals, composites, ceramics, addressing fatigue cracks, and delaminations/disbonds. Some fundamental issues related to Sonic IR imaging NDE are discussed in this paper as well.
A novel nondestructive imaging technique, thermosonics, which combines ultrasonic/sonic excitation and advanced infrared imaging, will be described. In this paper, the authors will illuminate the physical principles underlining this technique, and demonstrate its applications to detection of cracks in teeth.
We describe a new technique, Thermosonics, that can be used to detect cracks in teeth. This technique was initially invented and developed for finding cracks in industrial and aerospace applications. The thermosonics technique employs a single short pulse (typically tens of milliseconds) of ultrasound excitation combined with infrared imaging. Ultrasonic waves vibrate the target material. This vibration causes rubbing and clapping between faying surfaces of any cracks which are present, resulting in a temperature rise around the cracks. An infrared camera is used to image the temperature distribution during and after the ultrasound excitation. Thus, cracks in teeth can be detected. Although this technique is still under development, it shows promise for clinical use by dentists.
We describe progress in thermosonic crack detection. In this technique, a short single pulse of ultrasound is used to cause cracks to heat up and become visible in the infrared. A low frequency (say 10's of kHz) ultrasonic transducer infuses the sample with sound. Where cracks, disbonds, delaminations or other defects are present, the sound field causes the defect to heat locally. The technique is applicable to large and irregularly shaped objects. We present illustrative applications of this technology to aerospace, and automotive inspections.
We describe a new hybrid ultrasonic/infrared technology in which ha short single pulse of ultrasound is used to cause cracks to heat up and become visible in the infrared. A low frequency (say 10's of kHz) ultrasonic transducer infuses the sample with sound. Where cracks, disbonds, delaminations or other defects are present, the sound field causes the defect to heat locally. The technique is applicable to large and irregularly shaped objects. We present a variety of images to show the capability for this technique to image cracks and other defects in metals as well as other materials. Both surface-interrupting and subsurface cracks are imaged. The technique can utilize hand-held ultrasonic sources, is insensitive to the position of the source on the sample, and yields wide-area images, with the defects showing as bright (higher temperature) regions against a dark (lower temperature) background. It can be used for inspection of relatively inaccessible complex part geometries.
We describe fast infrared imaging of both static and dynamic crush tests on glass-fiber composite tubes. The results are compared with video images of the same tests.
The state-of-the-art of Thermal Wave Imaging as an NDE technique for Aging Aircraft is summarized. The technique is described, and examples are given of application to the thermal wave inspection of aircraft for such subsurface defects as corrosion, disbonded doublers, fluid intrusion, and delaminations of composite structures.
The principles of thermal wave imaging for NDE are described. The technique utilizes high-power photographic flash lamps for pulse-heating of the surface of the composite. The cooling of the surface is monitored by means of an IR video camera. Disbonds, delaminations, and inclusions are seen in the resultant thermal wave images, with deeper features appearing systematically at later times. Examples of the application of thermal wave imaging to nondestructive evaluation of boron fiber composite reinforcement patches, and graphite-fiber aerospace composite materials are described.
We describe an IR thermal wave imaging technique for making corrosion thinning determinations on aging aircraft skins. The technique uses pulsed surface heating and fast, synchronous IR imaging of subsurface structure, such as skin corrosion and disbonded doublers or tear straps. Sensitivity to corrosion thinning of less than two percent is demonstrated. Practical implementation of a simplified numerical measurement algorithm is presented, and the results are compared with profilometry and ultrasonic measurements of calibration standards. Examples are presented of thermal wave imaging of fuselage skin corrosion of a B737 testbed aircraft in a hangar environment at the FAA's Aging Aircraft NDI Validation Center.
We describe a thermal wave technique for making defect depth determinations. Both theory and experiment are presented, and the results are compared. Examples of defects having different lateral dimensions and boundary conditions are given.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.