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 Title
 VIBRATION ANALYSIS OF RECTANGULAR PLATES UNDER FLUID LOADING.
 Creator
 LEE, TZER CHIA., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

An energy method is presented for predicting the natural frequencies, radiation loss factor and system loss factor of simply supported rectangular plates under fluid loading. Both bare plates and plates with complete damping treatments are considered. Results obtained using the method developed are compared with two other theories. The agreement is generally good. The study points out the need for detailed analyses of plate vibration patterns and their associated radiation output under...
Show moreAn energy method is presented for predicting the natural frequencies, radiation loss factor and system loss factor of simply supported rectangular plates under fluid loading. Both bare plates and plates with complete damping treatments are considered. Results obtained using the method developed are compared with two other theories. The agreement is generally good. The study points out the need for detailed analyses of plate vibration patterns and their associated radiation output under various plate boundary conditions. There also exists a need for carefully conducted experimental work to verify the applicability of the current theory.
Show less  Date Issued
 1981
 PURL
 http://purl.flvc.org/fcla/dt/14086
 Subject Headings
 Plates (Engineering)Vibration
 Format
 Document (PDF)
 Title
 Vibrational power flow in thick connected plates.
 Creator
 McCollum, Michele D., Florida Atlantic University, Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

The total vibrational power flow in connected plate structures is investigated using an analytical "Power Flow" approach. The effects of shear and rotary inertia on the flexural wave transmission and the influence of inplane wave generation at structural discontinuities are included in the analytical model. In formulating a Power Flow model, the structure is divided into substructures whose responses may be determined analytically to obtain expressions for the input and transfer mobilities...
Show moreThe total vibrational power flow in connected plate structures is investigated using an analytical "Power Flow" approach. The effects of shear and rotary inertia on the flexural wave transmission and the influence of inplane wave generation at structural discontinuities are included in the analytical model. In formulating a Power Flow model, the structure is divided into substructures whose responses may be determined analytically to obtain expressions for the input and transfer mobilities of the substructures. For the case of platetype structures joined along a line, the mobilities are functions of both frequency and space. The power transmission between the individual plate substructures is then written as a function of these mobility expressions. The structure of concern in this dissertation consists of two plates connected in an Lconfiguration. In obtaining the expressions for the mobilities, the vibrational response of the individual plates is determined by solving the appropriate equations of motion. In this study the antisymmetric (flexural) motion is described using Mindlin's (1951) thick plate approximation to the threedimensional equations of motion. The applicability of this thick plate formulation is limited to frequencies below the frequency of the first antisymmetric mode of thicknessshear vibration of the plate. The symmetric (inplane) motion of the plates is described using the generalized theory of plane stress which neglects the direct coupling of the inplane motion with the thickness vibration modes, and is therefore valid only for frequencies which are lower than the frequency of the first mode of pure thickness vibration of the plate. The results for the power transmission in the Lplate obtained using the Power Flow formulation are verified at high frequencies by comparison with the results obtained using the Statistical Energy Analysis (SEA) technique. The SEA formulation for the Lplate is based on Mindlin's equations for flexural motion and the theory of generalized plane stress for inplane vibration. The results of the Power Flow formulation are verified at low frequencies by the results obtained using a Finite Element model of the Lshaped plate.
Show less  Date Issued
 1988
 PURL
 http://purl.flvc.org/fcla/dt/11929
 Subject Headings
 Plates (Engineering)Vibration
 Format
 Document (PDF)
 Title
 VIBRATION ANALYSIS OF RECTANGULAR PLATES WITH COMPLETE CONSTRAINEDLAYER DAMPING TREATMENTS.
 Creator
 CO, CHIMIN., Florida Atlantic University, Stevens, Karl K.
 Abstract/Description

An energy method for predicting the natural frequencies and loss factors of Rectangular Plates with Complete ConstrainedLayer Damping Treatments has been presented. Results obtained using the method developed were compared with those of two former theories. The agreement between the current theory and these two theories was generally good. There is a serious need for carefully conducted experimental work to verify the applicability of the current theory and of the various other laminated...
Show moreAn energy method for predicting the natural frequencies and loss factors of Rectangular Plates with Complete ConstrainedLayer Damping Treatments has been presented. Results obtained using the method developed were compared with those of two former theories. The agreement between the current theory and these two theories was generally good. There is a serious need for carefully conducted experimental work to verify the applicability of the current theory and of the various other laminated plate theories in existence. It is believed that the method of analysis presented can be extended to handle plates with partial constrainedlayer damping treatments.
Show less  Date Issued
 1981
 PURL
 http://purl.flvc.org/fcla/dt/14085
 Subject Headings
 Plates (Engineering)Vibration
 Format
 Document (PDF)
 Title
 The measurement of structural power flow in thin plate structures.
 Creator
 Padiyar, Satish., Florida Atlantic University, Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

An analytical and experimental investigation of the flow of vibrational power in a thin, Lshaped, finite plate structure subjected to mechanical and acoustic excitation is presented. In the analytical approach, mobility functions are used to determine the structural intensity vectors at various locations on the plate structure. Simulation results of intensity vectors estimated using three different measurement schemes are compared. The experimentally measured intensity vectors, for the case...
Show moreAn analytical and experimental investigation of the flow of vibrational power in a thin, Lshaped, finite plate structure subjected to mechanical and acoustic excitation is presented. In the analytical approach, mobility functions are used to determine the structural intensity vectors at various locations on the plate structure. Simulation results of intensity vectors estimated using three different measurement schemes are compared. The experimentally measured intensity vectors, for the case of mechanical excitation, using a four accelerometer array, are presented. They are found to match well with the results from the corresponding simulation. Similar results are obtained for the case of acoustic excitation of the Lshaped plate. The general pattern of the structural intensity vectors is found to be in agreement with the expected results.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14678
 Subject Headings
 Plates (Engineering)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 twentyfive 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.
Show less  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.
Show less  Date Issued
 1983
 PURL
 http://purl.flvc.org/fcla/dt/14188
 Subject Headings
 Plates (Engineering)Vibration, Damping (Mechanics)
 Format
 Document (PDF)
 Title
 Power flow analysis of a structure subjected to distributed excitation.
 Creator
 Cimerman, Benjamin Pierre., Florida Atlantic University, Cuschieri, Joseph M.
 Abstract/Description

An analytical investigation based on the Power Flow Method is presented for the prediction of vibrational Power Flow in simple connected structures subjected to various forms of distributed excitations. The principle of the power flow method consists of dividing the global structure into a series of substructures which can be analyzed independently and then coupled through the boundary conditions. Power flow expressions are derived for an Lshaped plate structure, subjected to any form of...
Show moreAn analytical investigation based on the Power Flow Method is presented for the prediction of vibrational Power Flow in simple connected structures subjected to various forms of distributed excitations. The principle of the power flow method consists of dividing the global structure into a series of substructures which can be analyzed independently and then coupled through the boundary conditions. Power flow expressions are derived for an Lshaped plate structure, subjected to any form of distributed mechanical excitation or excited by an acoustic plane wave. In the latter case air loading is considered to have a significant effect on the power input to the structure. Fluidstructure interaction considerations lead to the derivation of a corrected mode shape for the normal velocity, and the determination of the scattered pressure components in the expressions for the Power Flow.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14578
 Subject Headings
 Structural dynamics, Plates (Engineering)Vibration
 Format
 Document (PDF)
 Title
 VIBRATION ANALYSIS OF RECTANGULAR PLATES WITH COMPLETE AND PARTIAL CONSTRAINEDLAYER DAMPING TREATMENTS.
 Creator
 HSU, HONGYUAN., 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 constrainedlayer 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 constrainedlayer...
Show moreA theoretical analysis for predicting the system loss factors and natural frequencies of rectangular plates with complete and partial constrainedlayer 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 constrainedlayer 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.
Show less  Date Issued
 1983
 PURL
 http://purl.flvc.org/fcla/dt/14160
 Subject Headings
 Damping (Mechanics), Vibration, Plates (Engineering)Vibration
 Format
 Document (PDF)
 Title
 An experimental study of the response of circular plates subjected to fluid loading.
 Creator
 Coulson, Robert Kenneth., Florida Atlantic University, Glegg, Stewart A. L.
 Abstract/Description

The interaction between vibrating structures and fluids can have a profound influence upon the natural frequencies of the structure's vibration. This study examines one specific structure; a thin circular plate with the rarely studied free edge condition. It starts by considering a completely free plate in a vacuum and then, using receptance matching, utilises this result to determine the effects, on the natural frequencies, of a centrally located driving rod. Then, using the same technique,...
Show moreThe interaction between vibrating structures and fluids can have a profound influence upon the natural frequencies of the structure's vibration. This study examines one specific structure; a thin circular plate with the rarely studied free edge condition. It starts by considering a completely free plate in a vacuum and then, using receptance matching, utilises this result to determine the effects, on the natural frequencies, of a centrally located driving rod. Then, using the same technique, a result for the drive admittance of the fluid loaded plate is adapted to predict the natural frequencies of the same structure when subjected to significant fluid loading. All these results are then compared to those obtained from experiments.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14605
 Subject Headings
 Plates (Engineering)Vibration, Acoustical engineering
 Format
 Document (PDF)
 Title
 A METHOD OF ANALYSIS FOR EVALUATING THE EFFECTIVENESS OF PARTIAL DAMPING LAYER TREATMENTS FOR SQUARE PLATES.
 Creator
 KUNG, CHUNHUA., 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 simplysupported and edgefixed bonndary conditions are considered. An impulse testing technique is used to provide an experimental verification of the analysis for the case of an edgefixed 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
 Mobility power flow analysis of an infinite cylindrical shell with an enclosed plate discontinuity.
 Creator
 Buchmann, Patrick Pierre., Florida Atlantic University, Cuschieri, Joseph M.
 Abstract/Description

A mobility power flow approach is used to study the response of an infinitelylong cylindrical shell with an internal plate discontinuity. The shell is excited by either a ring radial force or by a plane acoustic wave. The junction between the shell and the internal plate is assumed to be radially pinned such that inplane waves of the plate can be neglected. The junction forces are expressed in terms of the mobility functions of the plate and the shell. From knowledge of the junction forces...
Show moreA mobility power flow approach is used to study the response of an infinitelylong cylindrical shell with an internal plate discontinuity. The shell is excited by either a ring radial force or by a plane acoustic wave. The junction between the shell and the internal plate is assumed to be radially pinned such that inplane waves of the plate can be neglected. The junction forces are expressed in terms of the mobility functions of the plate and the shell. From knowledge of the junction forces and velocities, the power input, the power flow from the shell to the plate, the shell response and the radiated farfield scattered pressure are determined for the circumferential mode n = 0. The results show how the energy propagates from one structure to the other, and present a very clear picture of the characteristics of the scattering pattern from the junction forces.
Show less  Date Issued
 1994
 PURL
 http://purl.flvc.org/fcla/dt/15113
 Subject Headings
 Shells (Engineering)Vibration, Plates (Engineering)Vibration, Structural dynamics, Vibration
 Format
 Document (PDF)
 Title
 Dynamic response of plate structures to external excitations.
 Creator
 Mani, George., Florida Atlantic University, Yong, Yan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

The dynamic response of plate structures composed of rigidly connected thin plates subjected to point loads is studied. The finite strip method combined with a new approach for analyzing periodic structures is utilized to obtain substantial reduction in computational efforts. Each strip with various boundary conditions is treated as a waveguide capable of transmitting different wave motions. Wave scattering matrices are defined to characterize wave motions at boundaries, intersection of...
Show moreThe dynamic response of plate structures composed of rigidly connected thin plates subjected to point loads is studied. The finite strip method combined with a new approach for analyzing periodic structures is utilized to obtain substantial reduction in computational efforts. Each strip with various boundary conditions is treated as a waveguide capable of transmitting different wave motions. Wave scattering matrices are defined to characterize wave motions at boundaries, intersection of plates and where type of wave guides are changed. The results obtained from the application of the approach on various plate configurations are presented and discussed.
Show less  Date Issued
 1990
 PURL
 http://purl.flvc.org/fcla/dt/14661
 Subject Headings
 Plates (Engineering)Vibration, Finite strip method, Structural analysis (Engineering)
 Format
 Document (PDF)
 Title
 Vibration tailoring of inhomogeneous beams and circular plates.
 Creator
 Pentaras, Demetris., Florida Atlantic University, Elishakoff, Isaac, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

The vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semiinverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e...
Show moreThe vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semiinverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e. designing the structure that possesses the prespecified value. Apparently for the first time in the literature, several closedform solutions for vibration tailoring have been derived for vibrating inhomogeneous beams and circular plates. Twelve new closedform solutions for vibration tailoring have been derived for an inhomogeneous polar orthotropic plate that is either clamped or simply supported around its circumference. Also, the vibration tailoring of a polar orthotropic circular plate with translational spring is analyzed. There is considerable potential of utilizing the developed method for design of functionally graded materials.
Show less  Date Issued
 2006
 PURL
 http://purl.flvc.org/fcla/dt/13344
 Subject Headings
 Acoustical engineering, Plates (Engineering)VibrationMathematical models, Buckling (Mechanics), Structural analysis
 Format
 Document (PDF)
 Title
 A perturbation method for the vibration analysis of beams and plates with freelayer 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 frequencydependent 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.
Show less  Date Issued
 1989
 PURL
 http://purl.flvc.org/fcla/dt/12239
 Subject Headings
 GirdersVibration, Plates (Engineering)Vibration, Perturbation (Mathematics), Damping (Mechanics)
 Format
 Document (PDF)