Global ETD Search
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Showing 1 to 12 of 12 for “"Acousto-Ultrasonic"”.
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Statistical methods applied to acousto-ultrasonic technique
… techniques such as radiography , eddy-current or ultrasonics. Recently, a new technique known as the Acousto-Ultrasonic (AU) technique, has been developed and appears to hold promise as a method for the evaluation of composite material quality. Implementation of the AU method is examined using the …
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A physical model for the acousto-ultrasonic method
… a model, and comments on NDE application of the acoustoultrasonic method for composite materials are presented. The basis of this work is a set of experiments where a sending and a receiving piezoelectric transducer were both oriented normal to the surface, at different points, on aluminum …
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Acousto-Ultrasonic Evaluation of Cyclic Fatigue of Spot Welded Structures
An acousto-ultrasonic approach is used to explore the damage development in tensile shear spot welds during fatigue loading. There is reasonable data to support the hypothesis that a decrease in an AU signal is indicative of the presence of an internal crack and could be used for monitoring and …
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An acousto-ultrasonic system for the evaluation of composite materials
A presentation is given of an acousto-ultrasonic system for the evaluation of composite materials. First, a brief statement will be made on the acousto-ultrasonic technique and its relative worth compared to other nondestructive testing techniques as applied to composite materials. The following …
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Predicting mechanical performance of adhesively bonded joints based on acousto-ultrasonic evaluation and geometric weighting
… a detailed image of the bonded joint, while acousto-ultrasonic measurements have been used to evaluate the stress transfer capability of modified lap shear joints. Knowledge of the stress distribution in the joint has provided a means of identifying critical areas of interest in the joint. …
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A feasibility study of the acousto-ultrasonic technique to assure the quality of adhesively bonded sheet metal
… The objective is to study the feasibility of Acousto-Ultrasonics (AU) as a nondestructive technique for assuring the quality of adhesively bonded sheet-metal used for automobiles. Other nondestructive (NDT) techniques were also applied viz., ultrasonics. radiography and thermography to …
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The development of an interpretive methodology for the application of real-time acousto-ultrasonic NDE technique for monitoring damage in ceramic composites under dynamic loads
… directed towards developing a near real-time, acousto-ultrasonic (AU), nondestructive evaluation (NDE) tool to study the failure mechanisms of ceramic composites. Progression of damage is monitored in real-time by observing the changes in the received AU signal during the actual test. During …
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A feasibility study of PVDF piezoelectric sensors to detect damage in adhesive joints
… in pulse-echo, through-transmission, and acousto-ultrasonic techniques to monitor curing, to detect porosity and crack propagation in different model joint geometries. The potential of using these techniques for practical bonded structures has then been evaluated.
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Nondestructive evaluation of complex geometry advanced material components
… this task and discuss the feasibility of the acousto-ultrasonic material characterization method for meeting these challenges. Particular attention will be given to implementing this methodology in an automated, cost effective manner. Work that is in progress involving laser in/out ultrasonic …
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Nondestructive evaluation of a high temperature ceramic matrix composite material
… increased crystallinity of the Nicalon fibers. Acousto-ultrasonic results indicated that thermal exposure altered the ability of the CMC specimens to transmit ultrasonic energy. The ability to transmit energy was degraded or enhanced depending on ageing temperature and the presence or absence of …
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Lamb wave propagation in laminated composite plates
… A simple method, similar in configuration to the acousto-ultrasonic technique, was used to measure Lamb wave phase velocities. Low frequency Lamb waves, usually in the range of 10 kHz to 1 MHz, were generated. Dispersion curves of the lowest symmetric Lamb mode and the lowest antisymmetric Lamb …
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Detection and assessment of wood decay – glulam beams and wooden utility poles
… report documents the development of acoustic and ultrasonic inspection methods on wooden glulam beams and utility poles. All beams and poles examined where composed of Douglas-fir. The report begins with a description of the structure of trees, the mechanical behavior of wood subjected to rot, and …