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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"longitudinal wave"”.
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Longitudinal Wave Propagation in Liquid Lines of Finite Length Including the Effect of Nonlinear Boundary Conditions
Made available in DSpace on 2015-05-12T21:43:44Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7013507.PDF: 545638 bytes, checksum: 9a6c27b0792a3aac52fec670c06d704b (MD5) Previous issue date: 1969
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Thin -Film Adhesion Measurement by Laser -Induced Stress Waves
… prism so that a high strain rate shear wave is generated and then allowed to impinge upon the test film. By allowing the initial longitudinal wave to mode convert to a shear wave and a secondary longitudinal wave at the oblique surface, mixed-mode loading of the thin film interface is …
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ΑΣΥΠΤΩΤΙΚΗ ΣΥΜΠΕΡΙΦΟΡΑ ΤΗΣ ΕΝΕΡΓΕΙΑΣ ΒΙΣΚΟΕΛΑΣΤΙΚΩΝ ΚΥΜΑΤΩΝ
… THE ENERGY OF THE TRANSVERSE AS WELL AS OF THE LONGITUDINAL WAVE IS PRESERVED (AND CONSEQUENTLY THE TOTAL ENERGY). THE ASYMPTOTIC ANALYSIS OF THE KINETIC AND STRAIN ENERGY INTEGRALS PROVES THE ASYMPTOTIC (AS T -> T ) EQUIPARTITION OF THE TOTAL ENERGY.
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Ultrasonic inspection methods for defect detection and process control in roll-to-roll flexible electronics manufacturing
… the use of ultrasound, specifically Lamb and longitudinal waves, as a sensing modality and measurement technique for thin film roll-to-roll manufacturing. A variety of custom wedges were designed and machined from multiple materials to test their suitability at launching ultrasonic Lamb waves …
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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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Holographic determination of mechanical properties and behaviour of materials
… relationship E=v²p, where v is the velocity of a longitudinal wave propagating in a long rod and p is the density of the rod. The technique of double-exposure holographic interferometry was used to record longitudinal waves propagating in long brass and steel rods. The waves were initiated by …
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Multi-axial failure of high-performance fiber during transverse impact
… effect of projectile nose geometry on ensuing wave development in high-performance yarns is explored during single yarn transverse impact. Special attention has been placed on visualizing the immediate region around the projectile-yarn contact site for 0.30-cal round, 0.30-cal fragment …
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Detection of in-plane stress waves with Polyvinylidene Fluoride (PVDF) sensors
… PVDF sensors for detection of in-plane stress waves in 31 and 32 modes. This was achieved by focusing on aspects of PVDF sensing related to determination of impact force, detection of stress wave propagation, and the stress averaging effect of PVDF sensors.</p><p>An experimental method was …
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The use of shaped explosive charges to investigate permeability, penetration, and fracture formation in coal, dolomite and plexiglas
… and highspeed photography and indicated that longitudinal wave velocity, Young's modulus, and tensile strength are related to penetration depth"--Abstract, page ii.
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Brillouin scattering from opaque semiconducting alloys and thin films
… Scattering from both surface and bulk acoustic waves were used to derive information on the elastic and dielectric constants of AlxGal_xAs alloys. The surface acoustic wave velocities along the [100] and [110] axes were measured for a number of aluminum concentrations. In samples that were …
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Cylindrical photonic crystals
… the properties of cylindrical photonic crystal waveguides in which light is confined laterally by the band gap of a cylindrically-layered photonic crystal. We show in particular that axially-uniform photonic band gap waveguides can exhibit novel behavior not encountered in their traditional …
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Time domain mathematical model for six-degree-of-freedom motion in a wave
… a six-degree-of-freedom motion of a ship in a wave. This integrated mathematical model is developed with its fundamental base on both traditional seakeeping and manoeuvring theories and thus obtaining of hydrodynamic data sets as well as formulation of force component are needed in a …
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Advancements in the Split Hopkinson Bar Test
… striking the end of a bar, a compressive stress wave is generated that immediately begins to traverse towards the specimen. Upon arrival at the specimen, the wave partially reflects back towards the impact end. The remainder of the wave transmits through the specimen and into the second bar, …
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The effect of geometry on acoustic emission.
Acoustic emissions are impulsive elastic waves which are part of the total energy release from many metallurgical phenomena. The emissions signature carry information about the source mechanisms and the present interest of investigators is to identify the acoustic emission sources in terms of …
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Nonlinear ultrasonic testing using a non-collinear approach: application to heat treatment of steels and to asphalt concrete mixtures
… micro-structural dependence of acoustic wave attenuation, velocity, and a non-linear parameter, non-collinear scattered wave amplitude. Specimens of various microstructures were prepared by means of heat treatment for 1045 and 4140 Steel. Nonlinear investigation was also performed on two …
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Frequency Dependent Mechanical Properties of Elastic Metamaterials with Locally Resonant Microstructures
… derivation and verified by the tone burst wave propagation using FE simulation. Further, the dynamic behavior of rods made of elastic metamaterials with frequency dependent properties was investigated. Based on the frequency dependent mass density and Young’s modulus for the effective …
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Theoretical and Experimental Studies of Manipulation of Elastic Waves in Helix Metamaterials
… control strategies for low-frequency elastic wave bandgaps remain limited, making large-range tunability within the low-frequency domain difficult. Therefore, widening the low-frequency bandgap, enhancing elastic wave attenuation, and achieving tunable control are critical for the practical …
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Ultrasonic wave reflection measurements on self-compacting pastes and concretes
… of this study was to extend the use of combined longitudinal (P-wave) and shear (S-wave) ultrasonic wave reflection (UWR) to monitor the setting and stiffening of self-compacting pastes and concretes. An additional objective was to interpret the UWR responses of various modified cement pastes. A …