The Experts below are selected from a list of 52095 Experts worldwide ranked by ideXlab platform
Hongliang Cui - One of the best experts on this subject based on the ideXlab platform.
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broadband stepped frequency modulated continuous terahertz wave tomography for non destructive Inspection of polymer materials
Polymer Testing, 2019Co-Authors: Xiaoxuan Zhang, Qijia Guo, Tianying Chang, Hongliang CuiAbstract:Abstract An all-solid-state electronic three-dimensional terahertz tomography system designed specifically for Non-Destructive Inspection of polymer materials is demonstrated, which is capable of determining the positions and shapes of hidden defects accurately. The imaging radar system, based on stepped-frequency modulated continuous wave (SFMCW), with center frequency at 180 GHz, bandwidth of 60 GHz, and average power 0.5 mW, is tested against thick Teflon (polytetrafluoroethylene, PTFE) plates with internal voids as samples. The locations and shapes of the hidden holes are obtained in both electromagnetic simulation and experimental measurements with a three-dimensional image reconstruction algorithm, which features advantages of accurate reconstructed image details and fast computation speed, demonstrating that the terahertz imaging radar system combined with the algorithm developed is capable of detecting internal defects of thick polymers. Key resolution parameters are established experimentally in detail, demonstrating 2.5 mm and 1.7 mm range resolutions in free space and in Teflon separately, and lateral spot diameters ranging from 3.4 mm to 8 mm at imaging distances from 5 mm to 60 mm.
Steve Ward - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation on magnetic flux leakage evaluation at high speed
Ndt & E International, 2006Co-Authors: Yong Li, Gui Yun Tian, Steve WardAbstract:High-speed Non-Destructive Inspection (NDI) systems using magnetic flux leakage method (MFL) is in great demand in online metal Inspection and defect characterisation, especially in pipeline and rail track Inspection. For MFL systems at high speed measurement, in addition to magnetic flux, eddy currents exist in metal specimen because of the relative movement between the probe and specimen. These currents alter the profile of electromagnetic field, which increases difficulty in signal interpretation and defect characterization. In this paper, eddy currents generated by high speed movement and their characterisation in high-speed MFL Inspection systems were investigated by using numerical simulations. Besides, the MFL signals from high speed MFL measurement against defect depth were examined.
Ryoichi Fukasawa - One of the best experts on this subject based on the ideXlab platform.
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terahertz imaging widespread industrial application in non destructive Inspection and chemical analysis
IEEE Transactions on Terahertz Science and Technology, 2015Co-Authors: Ryoichi FukasawaAbstract:Terahertz imaging is being applied to Non-Destructive Inspection and chemical analysis. The main advantage of this approach is that electromagnetic waves at terahertz frequencies can penetrate non-conductive materials and also provide the material’s spectral response. The application of terahertz imaging is rapidly spreading to fields such as the evaluation of industrial materials and pharmaceutical products, examination of works of art, investigation of cultural assets, quality control in manufacturing processes, diagnosis of buildings, detection of dangerous objects, biomedical diagnostics and more. This paper describes imaging methods which use terahertz pulses and terahertz camera technology. In addition, interesting applications are introduced from the view point of practical use.
Kaiuwe Schroder - One of the best experts on this subject based on the ideXlab platform.
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evaluation of infrared thermography methods for analysing the damage behaviour of adhesively bonded repair solutions
Composite Structures, 2020Co-Authors: Ulrike Martens, Kaiuwe SchroderAbstract:Abstract For subsurface damage Inspection of bonded repair patches, Non-Destructive Inspection methods are needed. Additionally, monitoring the subsurface damage progress under loading is essential to gain knowledge for the repair design process. Infrared thermography is a temperature-based Non-Destructive Inspection method. The method of optical lock-in thermography is commonly used for the steady-state detection of subsurface inhomogeneities while passive thermography can be used to monitor changes in surface temperature due to thermal energy dissipation. Here, the progress of subsurface damages is of interest. Both methods are analysed in terms of their applicability to monitor subsurface damage propagation under loading. This paper shows how these methods contribute to understand the degradation process of a mechanically loaded patch repair.
Steven C Lovejoy - One of the best experts on this subject based on the ideXlab platform.
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acoustic emission testing of beams to simulate shm of vintage reinforced concrete deck girder highway bridges
Structural Health Monitoring-an International Journal, 2008Co-Authors: Steven C LovejoyAbstract:The practical application of Acoustic emission (AE) testing in the Structural Health Monitoring (SHM) of vintage steel reinforced concrete highway bridges has been recently investigated by the Oregon Department of Transportation (ODOT) and Oregon State University (OSU). A large number of full scale laboratory test beams designed to simulate a particular class of highway bridge structure and a particular type of structural damage were tested with AE. The results of the AE test data analyzed using the Felicity and Calm ratios are presented and related to physically observed structural damage. New thresholds on the Felicity and Calm ratios specific to this class of structure and loading are suggested (based on the test results) to be used in both the damage assessment diagrams developed in the Japanese Non-Destructive Inspection Standard NDIS-2421 and implementation into a SHM program currently under development at ODOT.
