Study of a New Global Damage Detection Scheme for Disk-type Structures PDF Download

Author: Muhammad S. Shohel
Publisher:
ISBN:
Category : Civil engineering
Languages : en
Pages : 226

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Author: Seksan Ratanasumritkul
Publisher:
ISBN:
Category : Civil engineering
Languages : en
Pages : 138

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Author: Dabit Acharya
Publisher:
ISBN:
Category : Civil engineering
Languages : en
Pages : 228

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"The main objective of this study is to show the specific capabilities of the Scanning Laser Vibrometer (SLV) for global damage detection using a recent defect energy parameter technique proposed by Saleeb and coworkers. The experimental technique used for extraction of signature is the first and most important part in any damage detection technique. Signatures considered here are full-field SLV measurements for modal shapes and associated frequencies of plated structures. The damage feature extraction capability was studied extensively by analyzing various simulation and experimental results. The practical significance in structural health monitoring is that the detection at early stages of small-size defects is always desirable. The amount of changes in the structure{u2019}s response due to these small defects was determined to show the needed level of accuracy in the experimental methods. The signal noise ratio of experiment shows the capability of the same experiment to be used for damage detection purpose. Various experiments were performed to verify a significant signal noise ratio for a successful detection. Very high number of scanning points, for optical experimental measurement, for any civil structure can be impractical and uneconomical. So, a pragmatic direction for the development of new experimental measurement tools was studied where different number of scanning points and different types of statically loaded simulations were performed to verify the specific capabilities of the defect energy parameter technique. It was further observed that powerful graphic user interface should also be an integral part in any present in the damage detection scheme for successful and more accurate detection. Furthermore, some potential use of SLV techniques in detection are provided, both for dynamic and static applications."--abstract.

Author: Andrew Stephen Ward
Publisher:
ISBN: 9781124665467
Category :
Languages : en
Pages :

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Damage detection and localization allow for automated real-time monitoring of realworld engineering projects. The benefits of such a system include improved safety, lower maintenance costs, and higher reliability. Many of the early works focus almost exclusively on numerical simulations of real systems, with very little experimentally acquired data used in detection. Introducing real world data complicates the analysis significantly by requiring noise reducing techniques to acquire legitimate results. In addition, the cost of obtaining enough data to fully define a damaged system can quickly become prohibitive. This thesis focuses directly on damage detection schemes carried out through empirical means. First a concept proving scheme is used by which data about the system is collected through accelerometer data. The damage detection scheme requires the reduction of a large set of data to one or two descriptive eigenparameters. Second, the scheme is repeated using optically gathered data through useof a high speed camera and software image manipulation tools. Damage detection is shown to be possible under the some conditions and initial parameters. Localization of the damage, however, is shown to require sensor information from multiple locations. Further still the optically based method is shown to supplement a failed detection by other means.

Author: American Institute of Aeronautics and Astronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1224

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Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 400

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Author: National Intelligence Council
Publisher: Cosimo Reports
ISBN: 9781646794973
Category :
Languages : en
Pages : 158

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Book Description
"The ongoing COVID-19 pandemic marks the most significant, singular global disruption since World War II, with health, economic, political, and security implications that will ripple for years to come." -Global Trends 2040 (2021) Global Trends 2040-A More Contested World (2021), released by the US National Intelligence Council, is the latest report in its series of reports starting in 1997 about megatrends and the world's future. This report, strongly influenced by the COVID-19 pandemic, paints a bleak picture of the future and describes a contested, fragmented and turbulent world. It specifically discusses the four main trends that will shape tomorrow's world: - Demographics-by 2040, 1.4 billion people will be added mostly in Africa and South Asia. - Economics-increased government debt and concentrated economic power will escalate problems for the poor and middleclass. - Climate-a hotter world will increase water, food, and health insecurity. - Technology-the emergence of new technologies could both solve and cause problems for human life. Students of trends, policymakers, entrepreneurs, academics, journalists and anyone eager for a glimpse into the next decades, will find this report, with colored graphs, essential reading.

Author: Yunze He
Publisher: Butterworth-Heinemann
ISBN: 0128128364
Category : Technology & Engineering
Languages : en
Pages : 376

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Book Description
Transient Electromagnetic-Thermal Nondestructive Testing: Pulsed Eddy Current and Transient Eddy Current Thermography covers three key areas of theories, methods and applications, primarily the multi-physics field, including eddy current, heat conduction and Infrared radiation for defect evaluation, lateral heat conduction, which is analyzed to detect parallel cracks, and longitudinal heat conduction, which is analyzed to detect depth defect, or that which is beyond skin depth. In addition, the book explores methods, such as time domain, frequency domain and logarithm domain, also comparing A-scan , B-scan and C-scan. Sections on defect identification, classification and quantification are covered, as are advanced algorithms, principal components analysis (PCA), independent components analysis (ICA) and support vector machine (SVM). The book uses a lot of experimental studies on multi-layer aluminum structures, honeycomb structure, CFRP in the aerospace field, and steel and coating in the marine rail and transportation fields. Presents two kinds of transient NDT testing, from theory and methodology, to applications Includes time domain frequency domain and logarithm domain, which are all analyzed Introduces A-scan , B-scan and C-scan, which are compared Provides experimental studies for real damages, including corrosion and blister in steel, stress in aluminum, impact and delamination in CFRP laminates and RCF cracks are abundant

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 456

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Author: Michael Perryman
Publisher: Cambridge University Press
ISBN: 1108419771
Category : Science
Languages : en
Pages : 973

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Book Description
A complete and in-depth review of exoplanet research, covering the discovery methods, physics and theoretical background.