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Showing 1 to 20 of 38 for “"guided waves"”.
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Guided Waves in Plasma Media
Made available in DSpace on 2014-12-08T22:23:54Z (GMT). No. of bitstreams: 1 6607765.pdf: 4483803 bytes, checksum: 82a1c0503952e486bbba8af71c7a3bbc (MD5) Previous issue date: 1966
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Structural assesment of joints in satellites using guided waves
The intention of the Air Forces Responsive Space Initiative Project is to develop procedures and technologies necessary to produce a satellite within six days from the initial order. Modular satellite designs have been proposed to help streamline the process of preparing a satellite for deployment. …
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Monitoring Early Age Cementitious Materials Using Ultrasonic Guided Waves
… materials can be monitored using ultrasonic guided waves.
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Estimation of asphalt binder viscosity using ultrasonic guided waves
… From the results of this study, the proposed guided wave system is suggested for further study and eventual implementation in the asphalt industry.
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Formation property estimation from guided waves in a borehole
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1987.
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New Constraints on Fault-Zone Structure from Seismic Guided Waves
… rupture and seismic hazards. Fault zone seismic guided waves (GW) carry important information about internal structure of the low-velocity fault damage zone. Numerical modeling of observed FZGWs has been used to construct models of FZ structure. However, the depth extent of the waveguide and the …
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The detection of defects in tubes and plates using guided waves
Eddy current testing is the non-destructive test method of choice for the inspection of condenser tubes. However, unplanned shutdowns of power stations, due to unexpected condenser tube failures, still occur despite rigorous eddy current inspection programs. In addition to the improvement required …
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Nonlinear ultrasonic guided waves for quantitative life prediction of structures with complex geometries
… from harmonic generation for propagating elastic waves. The long term goal of this study is to investigate the non-linear elastic propagation in parts with complex geometry. Cellular Automata is introduced as a new simulation method, in order to develop new analysis on quadratic non-linearities. …
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Guided Waves Technique for Measurement of Contained Stress in Uniform Slender Elastic Bodies
… frequency, followed by a comparison with guided wave theory, allow extraction of the wavenumbers associated with all the propagating and evanescent modes in the body. The wavenumber associated with the bending mode is in turn related to contained stress and to the intrinsic rigidity of the …
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Detection of multiple defects based on structural health monitoring of pipeline using guided waves technique
… the Structural Health Monitoring (SHM) based on guided wave techniques for monitoring steel pipeline continuously in detecting and locating multi-damages. These multi damages include the circumference, hole and slopping cracks. A physical experimental works as well as numerical simulation using …
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Investigation of Linear and Nonlinear Torsional Guided Waves in Hollow Circular Cylinders for Damage Detection
… One of the promising options is the use of guided wave for damage detection in engineering applications, such as pipeline and truss system. Common types of damage in the structures include cracks and corrosion. Guided wave is sensitive to cracks up to micro scale. Long range inspection is …
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Spectral finite element modelling and damage identification of beam-like structures using linear and nonlinear guided waves
… approach for damage identification using guided waves. The proposed approach requires no baseline data. It can identify multiple damages such as characterising the number, location and the size of cracks in isotropic beams and delaminations in composite beams efficiently and accurately …
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Theory and Application of Joint Time-Frequency Analysis On Health Monitoring of Electric Cable and Guided-Waves Detection of Structural Corrosion
<p>The failure of both electric cable in a electric system and pipes in a gas or petroleum transportation system can cause disastrous consequence. It is important to monitoring the health of electric cable and critical pipeline in order to prevent accidents and save repair expenses. In both …
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Seismic effects of the Caloris basin impact, Mercury
… formed as a consequence of focused seismic waves generated by the massive impact event. In this paper, we revisit the antipodal seismic focusing effects of the Caloris impact by developing physically consistent structure models for Mercury and parameterized seismic source models for the …
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Efficient perturbative framework for coupling of radiative and guided modes in nearly periodic surfaces
… for computing the coupling of radiative and guided waves in slowly varying (nearly uniform or nearly periodic) surfaces, which is especially relevant to the exploitation of nonlocal effects in large-area metasurfaces. Our framework bridges a gap in the theory of slowly varying surfaces: aside …
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Microseismic guided wave eigenfunction theory with application to event depth classification in the Eagle Ford shale
The properties of guided waves that propagate in deep low-velocity zones are investigated using eigenfunction theory, and a novel application for microseismic event depth constraint to an unconventional reservoir is developed. Eigenfunctions, historically used in the analysis of Rayleigh and Love …
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Fundamental Studies In the Lamb-Wave Interaction Between Piezoelectric Wafer Active Sensor and Host Structure During Structural Health Monitoring
… the structure by exciting and receiving Lamb waves propagating in the structure or by passively listen to changes in the structure. PWAS-structure interaction modeling is fundamental in order to achieve single mode excitation, i.e., tuning, a requirement for most of the SHM algorithms (time …
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Acoustic scattering of spherical directional waves by smooth and statistically rough solid elastic cylinders
Realistic sonars radiate spherically spreading waves and have directivity. Therefore, they insonify a target over a finite number of Fresnel zones and span a continuum of oblique incident angles, even when the center of the beam is at normal incidence. These effects strongly influence both the …
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Acoustic scattering of spherical directional waves by smooth and statistically rough solid elastic cylinders
Realistic sonars radiate spherically spreading waves and have directivity. Therefore, they insonify a target over a finite number of Fresnel zones and span a continuum of oblique incident angles, even when the center of the beam is at normal incidence. These effects strongly influence both the …
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