Estimation of flexural wave energy parameters using wavenumber transform techniques
Abstract
The analysis of energy flow in complex, built-up structures at high frequencies requires new methods due to well-documented problems with other analysis approaches. Current analysis tools cannot be used to model the spatial variations of the response or are computationally expensive. Energy flow analysis addresses these aspects but introduces several new problems. In particular, energy flow analysis requires data about the energy flow, loss factor, and group speed of a structural element and the power reflection and transmission characteristics of joints that connect structural elements. It is not always possible to estimate all of these required energy flow analysis parameters analytically and existing experimental techniques are poorly adapted to this purpose. Thus, new experimental alternatives are required. A series of wavenumber domain techniques are investigated for structures composed of beam elements. Methods for the estimation of energy density, energy flow, group speed, loss factor, and flexural wave power reflection and transmission coefficients of joints are developed. The methods meet the goal of providing a simple engineering method for the experimental analysis of energy flow in complex, built-up structures. The techniques can be used to estimate energy flow analysis parameters at high frequencies, in the presence of measurement noise, and in situ. One set of appropriately acquired data can be analyzed to estimate all of the energy flow analysis parameters. Case studies of several structures are presented that demonstrate the utility of the wavenumber domain techniques.
Degree
Ph.D.
Advisors
Bernhard, Purdue University.
Subject Area
Mechanical engineering|Acoustics
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