Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Vibration

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 211 - 225 of 225

Full-Text Articles in Engineering

Component Mode Synthesis-Based Design Methodology For Structural Modification And Synthesis, Venkateshwarlu Maroju Apr 1995

Component Mode Synthesis-Based Design Methodology For Structural Modification And Synthesis, Venkateshwarlu Maroju

Mechanical & Aerospace Engineering Theses & Dissertations

In this work, structural modification and synthesis techniques based on component mode synthesis are presented. The component mode synthesis method formulates the eigenvalue equation of an entire structure in terms of the vibration characteristics of individual components in the assembly. Through this functional relationship, the individual components are successfully treated as the design entities in the proposed methodology. Unlike conventional design modification techniques that can only treat the properties of the finite elements as the design variables, this technique uses the vibration and static responses of the individual components as the design entities. The sensitivity derivatives of the global responses …

Go to article

Vibration Of Point-Supported Rectangular Composite Plates, Serge Abrate Jan 1995

Vibration Of Point-Supported Rectangular Composite Plates, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A general approach is presented to study the free vibrations of rectangular symmetrically laminated composite plates with point supports by using the Rayleigh-Ritz method and the Lagrange multiplier technique for enforcing the zero displacement constraints at the support locations. Polynomial approximation functions are used, and the constitutive relationships are written in terms of four lamination parameters. With these lamination parameters, the number of design variables is reduced to a minimum, which is useful for design optimization purposes, while all symmetric lay-ups are considered. This paper illustrates how the lamination parameters can be used for optimal design of vibrating plates. Results …

Go to article

Vibratory Size Segregation Of Particulate Matter, Anthony La Rosa Oct 1993

Vibratory Size Segregation Of Particulate Matter, Anthony La Rosa

Theses

Size segregation imposed by vibration or shaking is an ubiquitous phenomenon whereby a large particle will rise to the top of a bed of smaller spheres upon vibration. Several mechanisms based on computer simulations have been proposed, however a complete theory remains elusive. The objective of this study was to perform experiments to study vibratory segregation of particles for varying size ratios and vibration parameters. More specifically, the rise time of a sphere from the bottom to the top of a vibrated bed was examined. It was found that the rise time decreased with an increase in amplitude for fixed …

Go to article

Fiber Enhanced Viscoelastic Damping Polymers And Their Application To Passive Vibration Control, Houchun Xia Jul 1993

Fiber Enhanced Viscoelastic Damping Polymers And Their Application To Passive Vibration Control, Houchun Xia

Mechanical & Aerospace Engineering Theses & Dissertations

A new composite damping material is investigated, which consists of a viscoelastic matrix and high elastic modulus fiber inclusions. This fiber enhanced viscoelastic damping polymer is intended to be applied to light-weight flexible structures as surface treatment for passive vibration control. A desirable packing geometry for the composite material is proposed, which is expected to produce maximum shear strain in the viscoelastic damping matrix. Subsequently, a micromechanical model is established in which the effect of fiber segment length and relative motion between neighboring fibers are taken into account. Based on this model, closed form expressions for the effective storage and …

Go to article

Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens Dec 1992

Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens

Mechanical Engineering Faculty Patents

An active vibration control device for controlling vibration in a cantilevered member and a method for the same are disclosed. The device is comprised of a cantilevered member having a longitudinal axis comprising a sensor mounted near the free end of the member to measure motion of the member in a transverse direction and to produce a corresponding signal. A force generating assembly is mounted to the member near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.

Go to article

Effect Of Transverse Vibration On The Capillary Limit Of A Wrapped Screen Wick Copper/Water Heat Pipe, Mark C. Charlton Dec 1992

Effect Of Transverse Vibration On The Capillary Limit Of A Wrapped Screen Wick Copper/Water Heat Pipe, Mark C. Charlton

Theses and Dissertations

The effect of transverse vibration on the capillary limit of a copper/water heat pipe with a tightly wrapped screen wick was investigated. The capillary limit was measured over a range of operating temperatures under static conditions. A bench-top shaker was used to provide vibration normal to the longitudinal axis of the pipe, and the capillary limit was measured at vibration frequencies of 30, 250, and 1000 Hz. At each of these frequencies, tests were run at vibration levels of 1.0, 2.5, and 5.0 G. The pipe was maintained at a zero degree inclination angle and power throughput was increased until …

Go to article

The Effect Of Polymethylmethacrylate Bone Cement Vibration On The Bone-Cement Interface, A. M. C. Thomas, D. J. W. Mcminn, M. Haddaway, I. W. Mccall Jan 1992

The Effect Of Polymethylmethacrylate Bone Cement Vibration On The Bone-Cement Interface, A. M. C. Thomas, D. J. W. Mcminn, M. Haddaway, I. W. Mccall

Cells and Materials

Low frequency vibration of polymethylmethacrylate (PMMA) bone cement reduces the viscosity of the cement by shear thinning. The effect of this low frequency vibration on the bone-cement interface was studied using microfocal radiography (MFR) and scanning electron microscopy (SEM). Effects were studied in-vitro and in-vivo. In-vitro, samples of Palacos low viscosity PMMA were placed on blocks of Kiel bone and vibrated. MFR and SEM demonstrated an improvement in the appearance of the bone-cement interface. In-vivo, PMMA was injected into the upper tibia of the dog. An assessment of the effect of high and low pressure injection, and the effect of …

Go to article

Solution To Eigenvalue Problems Of Antisymmetric Cross-Ply And Antisymmetric Angle-Ply Laminated Plates Using Affine Transformations, Zaffir A. Chaudry Dec 1984

Solution To Eigenvalue Problems Of Antisymmetric Cross-Ply And Antisymmetric Angle-Ply Laminated Plates Using Affine Transformations, Zaffir A. Chaudry

Theses and Dissertations

Using affine transformations and suitably recasting the buckling vibration differential equations, the eigenvalue problem of anti-symmetric cross-ply and antisymmetric angle-ply laminated rectangular plates has been reduced to a function of two strong material constants, the generalized rigidity ratio, whose range is in the closed interval from 0 to 1, and the ratio of principal lamina stiffness. With the reduction in number of constants an exhaustive parameter study of buckling and vibration solution trends, is possible. The buckling coefficients decrease with decreasing value of generalized rigidity ratio for both antisymmetric cross-ply and antisymmetric angle-ply laminates. For a given aspect ratio, and …

Go to article

Adaption And Optimization Of The Ibrahim Time Domain (Itd) Modal Parameter Identification Algorithm For Mini-Computer Use, Mary T. Cogeos Jan 1984

Adaption And Optimization Of The Ibrahim Time Domain (Itd) Modal Parameter Identification Algorithm For Mini-Computer Use, Mary T. Cogeos

Retrospective Theses and Dissertations

Conventional modal analysis is performed using FFT Analyzers with modal analysis software developed by one of many test/analysis software vendors. The analysis is performed in the frequency domain using frequency response functions. A recent advancement in modal analysis involves analyzing the measured free response of a structure in the time domain. The Ibrahim Time Domain (ITD) Algorithm is such a method which has been used and verified at government environmental test facilities. The ITD is an accurate numeric solution. Minimal operator interaction is required for proper performance of the algorithm. The results of the ITD Algorithm are far superior to …

Go to article

Modal Analysis By State Space Approach In Frequency Domain, Feliciano Feijo Jan 1983

Modal Analysis By State Space Approach In Frequency Domain, Feliciano Feijo

Retrospective Theses and Dissertations

This report tests a new procedure to identify the eigenvalue problem matrix "A" by utilizing the frequency response of a system in state-space for a given sinusoidal forcing input. Two sample identification tests are performed and a detailed explanation of both cases is presented. The method proved to be correct and the results obtained were accurate in both cases. A random error was then added to both sample tests in order to simulate real measuring conditions. Results indicate that it is more difficult to identify the "A" matrix of an undamped system. The error in the system must be very …

Go to article

The Optimum Design Of A Shock Absorber To Minimize The Force Transmitted To The Supporting Base Of A Vibrating Equipment, J. P. Singh May 1972

The Optimum Design Of A Shock Absorber To Minimize The Force Transmitted To The Supporting Base Of A Vibrating Equipment, J. P. Singh

Theses and Dissertations

The present study involved two types of analyses as a part of the investigation leading to the design of a shock absorber providing optimal vibration control and minimum transmissibility. Those two types of analyses were the following.

Go to article

Preliminary Design Of A Hydraulic Vibration Machine With Variable Amplitude And Frequency, Using Multistage Amplification And Feedback Control, Melvin Joseph Merrell May 1966

Preliminary Design Of A Hydraulic Vibration Machine With Variable Amplitude And Frequency, Using Multistage Amplification And Feedback Control, Melvin Joseph Merrell

Theses and Dissertations

Essentially there are three types of vibration machines mechanical, electrodynamic, and electrohydraulic (hydraulic). Each of these machines has characteristics which make it suitable for particular areas of use.

Go to article

The Vibration Response Of Laminated Orthotropic Plates, Max E. Waddoups Jr. Aug 1965

The Vibration Response Of Laminated Orthotropic Plates, Max E. Waddoups Jr.

Theses and Dissertations

The behavior of anisotropic materials has been the object of much recent research® The high strength to weight ratio needed by aerospace structures has necessitated the use of exotic, composite materials which generally exhibit anisotropic behavior® These materials cannot be fully utilized unless analytical techniques are used which take maximum advantage of their anisotropic behavior.

Go to article

Analysis Of The Transient Response Of A Flat Rotating Disk By Generalized Transforms, Kenneth Wayne Chase Sep 1963

Analysis Of The Transient Response Of A Flat Rotating Disk By Generalized Transforms, Kenneth Wayne Chase

Theses and Dissertations

The object of this thesis was to lay a foundation for a comprehensive study of the dynamic response of rotating members. This initial phase of the study includes a theoretical investigation and proposes experimental techniques for the determination of the stresses and strains in a thin, rotating disk with a concentric hole, subjected to transient shaft inputs. There are many practical applications of this problem including computor memory storage disks, turbine rotors, grinding wheels, saw blades, gears, optical reflectors, and solar sails for space vehicles.

Go to article

A Study Of The Vibration Characteristics Of A Thin Shell Hyperbolic Paraboloid, Farrin W. West May 1963

A Study Of The Vibration Characteristics Of A Thin Shell Hyperbolic Paraboloid, Farrin W. West

Theses and Dissertations

Recent progress in structural engineering has been marked by the increased use of thin shells as load carrying members. In particular, shells of revolution have been widely utilized in the missile industry whereas shells of arbitrary shape have been incorporated in the architectural design of today's modern buildings. Missile applications have been extensively studied both statically and dynamically. However, architechural applications have generally been limited to the statics problem with little consideration being given to the dynamic behavior of these unique structures.

Go to article

First Prev