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application of perturbation techniques to the vibration analysis of structures with viscoelastic coating modifications
Title
An application of perturbation techniques to the vibration analysis of structures with viscoelastic coating modifications.
Creator
Kelly, William Joseph, Jr., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Proper application of matrix perturbation theory to the structural modification of vibrating systems yields accurate results without resolving the eigenvalue problem. For this reason it seems that the method may require less computer time and cost in performing iterative type design work. This thesis investigates the application of first-order perturbation techniques to a torsional shaft system subject to viscoelastic damping treatment modifications. The modifications are of general form in...
Show moreProper application of matrix perturbation theory to the structural modification of vibrating systems yields accurate results without resolving the eigenvalue problem. For this reason it seems that the method may require less computer time and cost in performing iterative type design work. This thesis investigates the application of first-order perturbation techniques to a torsional shaft system subject to viscoelastic damping treatment modifications. The modifications are of general form in that the coating length and thickness are not restricted. Large modifications are built up by a series of small first-order perturbations. In addition to developing a better understanding of the usefulness of this application of perturbation theory, the goal of this paper is also to understand the nonproportional damping effects of partial viscoelastic coatings.
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Date Issued
1988
PURL
http://purl.flvc.org/fcla/dt/14455
Subject Headings
Vibration, Perturbation (Mathematics)
Format
Document (PDF)
perturbation method for the vibration analysis of beams and plates with free-layer damping treatments
Title
A perturbation method for the vibration analysis of beams and plates with free-layer damping treatments.
Creator
Shen, Sueming, Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The feasibility of using structural modification techniques to determine the effect of added viscoelastic damping treatments on the modal properties of a distinct eigenvalue system and a degenerate system is investigated. Linear perturbation equations for the changes introduced into the system eigenproperties are derived and applied to several examples involving the flexural vibration of beams and square plates with varying degrees of damping treatment. Both large and small perturbations are...
Show moreThe feasibility of using structural modification techniques to determine the effect of added viscoelastic damping treatments on the modal properties of a distinct eigenvalue system and a degenerate system is investigated. Linear perturbation equations for the changes introduced into the system eigenproperties are derived and applied to several examples involving the flexural vibration of beams and square plates with varying degrees of damping treatment. Both large and small perturbations are considered. An FEM code has been developed to compute the dynamic system parameters which are subsequently used in an iterative method to determine the modal properties. The perturbation approach described can accommodate temperature and frequency-dependent material properties, and the procedures involved are illustrated in the examples considered. Results obtained for these examples are compared with those available from closed form or finite element solutions, or from experiments. Excellent agreement of the results of the present method with those of other contemporary methods demonstrates the validity, overall accuracy, efficiency and convergence rate of this technique. The perturbation approach appears to be particularly well suited for systems with temperature and frequency dependent material properties, and for design situations where a number of damping configurations must be investigated.
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Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/12239
Subject Headings
Girders--Vibration, Plates (Engineering)--Vibration, Perturbation (Mathematics), Damping (Mechanics)
Format
Document (PDF)