An inverse acoustical phased array technique for impact detection and location

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Title An inverse acoustical phased array technique for impact detection and location
Publication Type thesis
School or College College of Engineering
Department Civil & Environmental Engineering
Author Papulak, Tyler Steven
Date 2012-05
Description Due to the complex failure modes associated with composites, a structural health monitoring system capable of accurately locating the source of strength-reducing events is desirable in order to reduce inspection time and time out of service. Various active and passive inspection techniques exist but most require large footprints and extensive cabling to monitor full scale structures. This work derives various location techniques by coupling modal acoustic emissions with phased array techniques to detect and accurately locate the source of strength-reducing events such as impacts. Phased array techniques provide a method to more accurately track phase points for determining arrival times used to back-calculate the source, as well as providing a method that can incorporate anisotropic wave speeds. To increase accuracy by neglecting local to global material changes, the local velocity profile per component was found and built into the derived location algorithms. The location algorithms were then tested on two full scale composite structures based on strength and stiffness critical design considerations. It was found that with two arrays, each with dimensions of 1 inches in width and 8 inches in length and consisting of four sensors each, events could be accurately located over a 65 ft2 region on the stiffness critical structure with an average error of 10 inches and over a 100 ft2 region on the strength critical structure with an average error of 9 inches.
Type Text
Publisher University of Utah
Subject Composites; impact detection and location; large structures; modal acoustic emissions; phased array; structural health monitoring
Subject LCSH Shock (Mechanics); Composite materials -- Mechanical properties; Composite materials -- Testing
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management © Tyler Steven Papulak
Format application/pdf
Format Medium application/pdf
Format Extent 2,500,468 bytes
Identifier us-etd3/id/653
Source Original in Marriott Library Special Collections, TA7.5 2012 .P26
ARK ark:/87278/s65m6mhq
Setname ir_etd
ID 194818
Reference URL https://collections.lib.utah.edu/ark:/87278/s65m6mhq
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