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Title: EXPERIMENTAL MODAL ANALYSIS OF A CIRCULAR PLATE WITH PARTIAL DAMPING TREATMENT.
Creator: LOPES, JAUPES BEANDAO., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Application of modal testing techniques in the determination of the modal parameters and mode shapes of an edge-fixed circular plate with a free-layer viscoelastic damping treatment extending over a portion of the plate surface is described. The mode shapes and modal parameters were determined for the first five flexural modes of the plate, which had a free-layer viscoelastic damping treatment on one side in the form of a central circular patch of varying size. The experimental setup and...
Show moreApplication of modal testing techniques in the determination of the modal parameters and mode shapes of an edge-fixed circular plate with a free-layer viscoelastic damping treatment extending over a portion of the plate surface is described. The mode shapes and modal parameters were determined for the first five flexural modes of the plate, which had a free-layer viscoelastic damping treatment on one side in the form of a central circular patch of varying size. The experimental setup and procedure is described in detail, with particular emphasis upon problems of modal overlap resulting from the symmetry of the test structure. Results comparing the predicted and measured natural frequencies and modal loss factors for varying degrees of damping treatment are presented for select cases.
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Date Issued: 1984
PURL: http://purl.flvc.org/fcla/dt/14223
Subject Headings: Damping (Mechanics), Mechanics, Analytic
Format: Document (PDF)

Title: A STUDY OF FRICTION DAMPING AS APPLIED TO VIBRATING STRUCTURES.
Creator: DESAI, VIJAY R., Florida Atlantic University, Cuschieri, Joseph M.
Abstract/Description: Of the many methods of introducing damping in vibrating structures, the dissipation of energy due to interfacial slip can significantly increase the damping loss factor. However, because of the lack of understanding and other phenomena such as fretting corrosion and loss of structural rigidity, friction damping is rarely used. A study was thus undertaken to investigate this complex phenomenon, with emphasis on trying to gain a better understanding of friction damping with certain parameters...
Show moreOf the many methods of introducing damping in vibrating structures, the dissipation of energy due to interfacial slip can significantly increase the damping loss factor. However, because of the lack of understanding and other phenomena such as fretting corrosion and loss of structural rigidity, friction damping is rarely used. A study was thus undertaken to investigate this complex phenomenon, with emphasis on trying to gain a better understanding of friction damping with certain parameters such as clamping pressure, frequency, magnitude of excitation and surface finish. Although the non-linearities associated with friction makes this mechanism difficult to model mathematically, finite element (FE) analysis shows some promise. Although the results obtained using an FE model were not exactly comparable to the experimental results, these analytical results did show the same general trends as observed in the experiments.
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Date Issued: 1987
PURL: http://purl.flvc.org/fcla/dt/14369
Subject Headings: Damping (Mechanics), Vibration
Format: Document (PDF)

Title: ANALYSIS OF DAMPING LAYER TREATMENTS FOR PLATES USING EXPERIMENTALLY DETERMINED MODE SHAPES.
Creator: JAISING, VINOD R., Florida Atlantic University, Stevens, Karl K.
Abstract/Description: A method of analysis is presented to determine the natural frequencies and loss factors of a plate covered with viscoelastic coating, using experimentally obtained mode shapes. The mode shapes for a square plate clamped on all edges are determined using an HP 5423 A Structural Dynamics Analyzer. A computer program, based on the method of analysis, is developed to determine the natural frequencies and loss factors of a rectangular plate covered with viscoelastic material, and clamped on all...
Show moreA method of analysis is presented to determine the natural frequencies and loss factors of a plate covered with viscoelastic coating, using experimentally obtained mode shapes. The mode shapes for a square plate clamped on all edges are determined using an HP 5423 A Structural Dynamics Analyzer. A computer program, based on the method of analysis, is developed to determine the natural frequencies and loss factors of a rectangular plate covered with viscoelastic material, and clamped on all edges. It was found that, for a fully coated plate, and for a mesh with twenty-five mesh points, the error in the fundamental frequency was approximately 5 percent. A comparison between the mode shapes for the bare plate and for the fully coated plate revealed no significant difference. It was also found that increasing the number of measurement points would not significantly improve the results.
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Date Issued: 1981
PURL: http://purl.flvc.org/fcla/dt/14050
Subject Headings: Plates (Engineering)--Vibration, Damping (Mechanics)
Format: Document (PDF)

Title: EXPERIMENTAL DETERMINATION OF NATURAL FREQUENCIES AND LOSS FACTORS OF A CLAMPED RECTANGULAR PLATE WITH PARTIAL CONSTRAINED LAYER DAMPING TREATMENTS.
Creator: BHAT, RAJENDRA AGHUT., Florida Atlantic University, Stevens, Karl K.
Abstract/Description: An experimental investigation to determine the effectiveness of partial constrained layer damping treatments for a clamped rectangular plate is described. The impulse testing technique was used with a Hewlett Packard '5423A structural Dynamics Analyzer' to determine modal parameters of the first five flexural modes. The results obtained are compared with theoretical results and they are in agreement. The results indicate that partial constrained layer damping treatments, if properly used, can...
Show moreAn experimental investigation to determine the effectiveness of partial constrained layer damping treatments for a clamped rectangular plate is described. The impulse testing technique was used with a Hewlett Packard '5423A structural Dynamics Analyzer' to determine modal parameters of the first five flexural modes. The results obtained are compared with theoretical results and they are in agreement. The results indicate that partial constrained layer damping treatments, if properly used, can be more effective than complete treatments.
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Date Issued: 1983
PURL: http://purl.flvc.org/fcla/dt/14188
Subject Headings: Plates (Engineering)--Vibration, Damping (Mechanics)
Format: Document (PDF)

Title: VIBRATION ANALYSIS OF RECTANGULAR PLATES WITH COMPLETE AND PARTIAL CONSTRAINED-LAYER DAMPING TREATMENTS.
Creator: HSU, HONG-YUAN., Florida Atlantic University, Stevens, Karl K.
Abstract/Description: A theoretical analysis for predicting the system loss factors and natural frequencies of rectangular plates with complete and partial constrained-layer damping treatments has been presented. This analysis is based upon an energy approach to the free vibration of plates. Results predicted were compared with those from experiments. Satisfactory agreement has been reached. Both the theoretical and the experimental results presented in this thesis indicate clearly that partial constrained-layer...
Show moreA theoretical analysis for predicting the system loss factors and natural frequencies of rectangular plates with complete and partial constrained-layer damping treatments has been presented. This analysis is based upon an energy approach to the free vibration of plates. Results predicted were compared with those from experiments. Satisfactory agreement has been reached. Both the theoretical and the experimental results presented in this thesis indicate clearly that partial constrained-layer damping treatments can provide effective, or even superior, amounts of damping, and that their use can lead to significant savings in material costs and weight.
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Date Issued: 1983
PURL: http://purl.flvc.org/fcla/dt/14160
Subject Headings: Damping (Mechanics), Vibration, Plates (Engineering)--Vibration
Format: Document (PDF)

Title: A METHOD OF ANALYSIS FOR EVALUATING THE EFFECTIVENESS OF PARTIAL DAMPING LAYER TREATMENTS FOR SQUARE PLATES.
Creator: KUNG, CHUN-HUA., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An energy method for predicting the natural frequency and loss factor for square plates with partial and complete coatings is developed. Both simply-supported and edge-fixed bonndary conditions are considered. An impulse testing technique is used to provide an experimental verification of the analysis for the case of an edge-fixed square plate. The analytical and experimental results are in close agreement, and indicate that partial coatings can provide effective damping treatments.
Date Issued: 1981
PURL: http://purl.flvc.org/fcla/dt/14045
Subject Headings: Plates (Engineering)--Vibration, Damping (Mechanics)
Format: Document (PDF)

Title: A METHOD OF ANALYSIS FOR EVALUATING THE EFFECTIVENESS OF PARTIAL DAMPING LAYER TREATMENTS FOR CIRCULAR PLATES.
Creator: SHOMSTEIN, SAMUEL COLEMAN., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis develops an approach for predicting the loss factors and natural frequencies of circular plates with partial and complete viscoelastic damping surface treatments. Plates with fixed and simply supported edges were considered. The analysis is based on an energy approach to the free vibration of plates. Results predicted were compared with those obtained experimentally by Lopes. Both the experimental and analytical studies clearly indicate that substantial amounts of material and...
Show moreThis thesis develops an approach for predicting the loss factors and natural frequencies of circular plates with partial and complete viscoelastic damping surface treatments. Plates with fixed and simply supported edges were considered. The analysis is based on an energy approach to the free vibration of plates. Results predicted were compared with those obtained experimentally by Lopes. Both the experimental and analytical studies clearly indicate that substantial amounts of material and added weight can be saved by using partial damping surface treatments.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14279
Subject Headings: Damping (Mechanics)--Analysis, Viscoelasticity--Experiments
Format: Document (PDF)

Title: Control of response of tall multi-story buildings under wind excitation.
Creator: Qiu, Xin., Florida Atlantic University, Lin, Y. K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Theoretical investigation is carried out into the extent to which floor accelerations of a wind-excited tall building can be reduced by increasing damping in those components in a building which are generally regarded to be non-structural elements, and by using active control. The wind loads are modeled as stochastic processes, which are correlation-stationary in time. Only the drag wind forces are considered in the analyses. The spectral densities and cross-spectral densities of two commonly...
Show moreTheoretical investigation is carried out into the extent to which floor accelerations of a wind-excited tall building can be reduced by increasing damping in those components in a building which are generally regarded to be non-structural elements, and by using active control. The wind loads are modeled as stochastic processes, which are correlation-stationary in time. Only the drag wind forces are considered in the analyses. The spectral densities and cross-spectral densities of two commonly used models, proposed by Davenport and by Simiu, are compared. The Davenport spectrum is used in the numerical calculation for illustration purposes. Several structural models are discussed: an ideal spatially periodic model, an ideal piece-wise spatially periodic model, a nominal spatially periodic model with random disorder in periodicity, and an ideal spatially periodic model equipped with an active mass damper control system. The problems are formulated using the transfer matrix approach in the frequency domain. Analytical solutions are obtained for the spectral densities and the mean-square values of the floor accelerations and those of the active control force. Numerical examples are given for illustration.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/12495
Subject Headings: Tall buildings--Aerodynamics, Wind-pressure, Damping (Mechanics)
Format: Document (PDF)

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)

Title: Rain-wind-induced cable vibrations in cable-stayed bridges.
Creator: Calle, Oscar F., Reddy, Dronnadula V., Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: This research is aimed at investigating and analyzing the rain-windinduced cable vibration phenomena experienced in cables of cable-stayed bridges and also the countermeasures employed by engineers to mitigate the large-amplitude vibration problem reported by various researchers around the world. In order to investigate the problem of the water rivulet creation at the top of the cable surface, a single-degree-of-freedom (SDOF) analytical model was developed and analyzed. This thesis studies...
Show moreThis research is aimed at investigating and analyzing the rain-windinduced cable vibration phenomena experienced in cables of cable-stayed bridges and also the countermeasures employed by engineers to mitigate the large-amplitude vibration problem reported by various researchers around the world. In order to investigate the problem of the water rivulet creation at the top of the cable surface, a single-degree-of-freedom (SDOF) analytical model was developed and analyzed. This thesis studies the aerodynamic instability of cables in cable-stayed bridges by doing literature review of a typical in-situ test, developing a single degree-of-freedom (SDOF) analytical model, and an ANSYS finite element model. Furthermore, a linear viscous damper that acts as a countermeasure to the large amplitudes of vibration is reported and analyzed. The suppression characteristics and damper effectiveness of such countermeasure are summarized.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004271, http://purl.flvc.org/fau/fd/FA00004271
Subject Headings: Bridges -- Aerodynamics, Bridges -- Vibration -- Prevention, Cable stayed bridges -- Maintenance and repair, Damping (Mechanics), Structural dynamics, Vibration -- Mathematical models, Wind resistant design
Format: Document (PDF)

Damping (Mechanics) (9)	+ -
Plates (Engineering)--Vibration (5)	+ -
Vibration (2)	+ -
Bridges -- Aerodynamics (1)	+ -
Bridges -- Vibration -- Prevention (1)	+ -

Cable stayed bridges -- Maintenance and repair (1)	+ -
Damping (Mechanics)--Analysis (1)	+ -
Girders--Vibration (1)	+ -
Mechanics, Analytic (1)	+ -
Perturbation (Mathematics) (1)	+ -
Structural dynamics (1)	+ -
Tall buildings--Aerodynamics (1)	+ -
Vibration -- Mathematical models (1)	+ -
Viscoelasticity--Experiments (1)	+ -
Wind resistant design (1)	+ -
Wind-pressure (1)	+ -

Florida Atlantic University (10)	+ -
Stevens, Karl K. (7)	+ -
College of Engineering and Computer Science (6)	+ -
Department of Ocean and Mechanical Engineering (5)	+ -
BHAT, RAJENDRA AGHUT. (1)	+ -

Calle, Oscar F. (1)	+ -
Cuschieri, Joseph M. (1)	+ -
DESAI, VIJAY R. (1)	+ -
Department of Civil, Environmental and Geomatics Engineering (1)	+ -
HSU, HONG-YUAN. (1)	+ -
JAISING, VINOD R. (1)	+ -
KUNG, CHUN-HUA. (1)	+ -
LOPES, JAUPES BEANDAO. (1)	+ -
Lin, Y. K. (1)	+ -
Qiu, Xin. (1)	+ -
Reddy, Dronnadula V. (1)	+ -
SHOMSTEIN, SAMUEL COLEMAN. (1)	+ -
Shen, Sueming (1)	+ -

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