Downloads & Free Reading Options - Results

Vibrations generated by machine driveline components can cause excessive noise and structural damage. Magnetostrictive materials, including Galfenol (iron-gallium alloys) and Terfenol-D (terbium-iron-dysprosium alloys), are able to convert mechanical energy to magnetic energy. A magnetostrictive vibration ring is proposed, which generates electrical energy and dampens vibration, when installed in a machine driveline. A 2D axisymmetric finite element (FE) model incorporating magnetic, mechanical, and electrical dynamics is constructed in COMSOL Multiphysics. Based on the model, a parametric study considering magnetostrictive material geometry, pickup coil size, bias magnet strength, flux path design, and electrical load is conducted to maximize loss factor and average electrical output power. By connecting various resistive loads to the pickup coil, the maximum loss factors for Galfenol and Terfenol-D due to electrical energy loss are identified as 0.14 and 0.34, respectively. The maximum average electrical output power for Galfenol and Terfenol-D is 0.21 W and 0.58 W, respectively. The loss factors for Galfenol and Terfenol-D are increased to 0.59 and 1.83, respectively, by using an L-C resonant circuit.

Vibrational analysis of rotating machinery is able to identify a large number of system ills. Shaft bow, shaft unbalance and coupling misalignments make up the major portion of the observed vibrational frequency spectra of rotating machinery. These vibrational spectra can be used to determine the type of rotating system abnormality, the degree of misalignment and the rate of alignment degradation. The proper joining of rotating machinery is a critical issue with high power and a high speed equipments. Couplings used to join machinery have a broad spectrum of characteristics and specific purposes. Couplings are used to compensate for axial, lateral and angular misalignments. In addition, couplings may exhibit constant or non-constant input versus output speed relationships. The importance of mating a driving and driven piece of equipment with the properly designed coupling is paramount. In the following report the author discusses numerous types of couplings, the behavioral characteristics of couplings and the considerations which must be taken into account when selecting a coupling for a rotating system. The analysis which follows list the various alignment discrepancies which can be detected by vibrational analysis and the requirements for non-constant and constant velocity characteristics of couplings. In addition, numerous types of couplings are catalogued and discussed. Theses. (FR)

Vibrational analysis of rotating machinery is able to identify a large number of system ills. Shaft bow, shaft unbalance and coupling misalignments make up the major portion of the observed vibrational frequency spectra of rotating machinery. These vibrational spectra can be used to determine the type of rotating system abnormality, the degree of misalignment and the rate of alignment degradation. The proper joining of rotating machinery is a critical issue with high power and a high speed equipments. Couplings used to join machinery have a broad spectrum of characteristics and specific purposes. Couplings are used to compensate for axial, lateral and angular misalignments. In addition, couplings may exhibit constant or non-constant input versus output speed relationships. The importance of mating a driving and driven piece of equipment with the properly designed coupling is paramount. In the following report the author discusses numerous types of couplings, the behavioral characteristics of couplings and the considerations which must be taken into account when selecting a coupling for a rotating system. The analysis which follows list the various alignment discrepancies which can be detected by vibrational analysis and the requirements for non-constant and constant velocity characteristics of couplings. In addition, numerous types of couplings are catalogued and discussed. Theses. (FR)

Contents: Structural Modifications by Viscoelastic Elements; Stochastic Dynamic Analysis of a Structure with Frictional Joints; Modal Analysis of Structural Systems Involving Nonlinear Coupling; Discrete Modifications to Continuous Dynamic Structural Systems; Reanalysis of Continuous Dynamic Systems with Continuous Modifications; A Pole-Free Reduced-Order Characteristic Determinant Method for Linear Vibration Analysis Based On Sub- Structuring; Determination of Shear Coefficient of a General Beam Cross Section by Finite Element Method; Gear Case Vibration Isolation in a Geared Turbine Generator; Effect of Coupled Torsional-Flexural Vibration of a Geared Shaft System on the Dynamic Tooth Load; Precision Measurement of Torsional Oscillations Induced by Gear Errors; Analysis by the Lumped Parameter Method of Blade Platform Friction Dampers Used in the High Pressure Fuel Turbopump of the Space Shuttle Main Engine; Transient Vibration Test Criteria for Spacecraft Hardware; Vibrational Loading Mechanism of Unitized Corrugated Containers with Cushions and Non-load-bearing Contents; Leakage-flow Induced Vibrations of a Chimney Structure Suspended in a Liquid Flow; Experimental Performance of an Off-road Vehicle Utilizing a Semi-active Suspension; and Effect of Air Cavity on the Vibration Analysis of Loaded Drums.

Contents: Structural Modifications by Viscoelastic Elements; Stochastic Dynamic Analysis of a Structure with Frictional Joints; Modal Analysis of Structural Systems Involving Nonlinear Coupling; Discrete Modifications to Continuous Dynamic Structural Systems; Reanalysis of Continuous Dynamic Systems with Continuous Modifications; A Pole-Free Reduced-Order Characteristic Determinant Method for Linear Vibration Analysis Based On Sub- Structuring; Determination of Shear Coefficient of a General Beam Cross Section by Finite Element Method; Gear Case Vibration Isolation in a Geared Turbine Generator; Effect of Coupled Torsional-Flexural Vibration of a Geared Shaft System on the Dynamic Tooth Load; Precision Measurement of Torsional Oscillations Induced by Gear Errors; Analysis by the Lumped Parameter Method of Blade Platform Friction Dampers Used in the High Pressure Fuel Turbopump of the Space Shuttle Main Engine; Transient Vibration Test Criteria for Spacecraft Hardware; Vibrational Loading Mechanism of Unitized Corrugated Containers with Cushions and Non-load-bearing Contents; Leakage-flow Induced Vibrations of a Chimney Structure Suspended in a Liquid Flow; Experimental Performance of an Off-road Vehicle Utilizing a Semi-active Suspension; and Effect of Air Cavity on the Vibration Analysis of Loaded Drums.

The setting of alarm levels plays a vital role in a machinery condition monitoring and diagnostic system. In this research, two approaches to setting vibration alarm levels using vibration signals produced by fire pumps are presented in the time and frequency domains. In the time domain, the cross peak analysis is proposed to extract the dominate peak points. The distribution of these cross peak points is found to have a lognormal distribution and can be normalized to a Normal distribution in the VdB domain. The computed g+2a value in the VdB domain is suggested for use as the alarm level. In the frequency domain, 1/1 octave band analysis is introduced. Three artificial fault simulations are conducted to compare the 1/1 octave band method with the broadband method. The results show that the 1/1 octave band method is more sensitive to the changes in VdB level than the broadband method. The computer programs to perform these two analyses are written using MATLAB. Alarm Level, Vibration, Fire Pump, Cross Peak Analysis, 1/1 Octave Band Analysis, Condition Monitoring and Diagnostics.

Partial contents: Equipment survivability on the integrated battlefield; Survivability requirements for future Air Force systems; Nuclear hardness validation testing; Changing dimensions of qualification testing; Required developments in structural dynamics; Effect of seals on rotor systems; Machinery vibration evaluation techniques; Shaft vibration measurement and analysis techniques; Spin test vibrations of pendulously supported disc/cylinder rotors; Modal analysis as a tool in the evaluation of a turbine wheel failure; Contribution the the dynamic behaviour of flexible mechanisms; Self-excited vibration of a nonlinear system with random parameters.

The isolation of machinery vibration from rigid and nonrigid substructures is described in uncomplicated terms. One- and two-stage mounting systems, single and multiple antivibration mountings, and beamlike and platelike substructures are examined. A machine and the intermediate mass of a two-stage mounting system are considered to be supported by flanges or feet to demonstrate the loss in isolation that can occur if the flanges are not rigid but are multiresonant because of their poor design. The use of conventional dynamic absorbers to reduce the vibration of such structural members as beams (rails and stanchions) and circular plates (bulkheads) is discussed. A novel dynamic vibration absorber is described that comprises a damped circular plate loaded centrally by a lumped mass and clamped at its perimeter to the vibrating item or structure of concern. (Author)

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Mechanical Engineering Section Name: Mechanical Vibration and Shock (MED 28) Designator of Legally Binding Document: IS/ISO 10055 Title of Legally Binding Document: Mechanical vibration - Vibration testing requirements for shipboard equipment and machinery components Number of Amendments: Equivalence: ISO 10055:1996 Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda

Source: Digital Library of India Scanning Centre: C-DAC, Noida Source Library: Central Library, Bits- Pilani Date Accessioned: 6/19/2015 17:15 The Digital Library of India was a project under the auspices of the Government of India.

Post-stressing concrete mat foundation reduces excessive vibrations in machinery. The mat is stressed in compression after the machinery is mounted, thus closing any cracks in it, altering the distribution of the soil subgrade reaction on the mat, and changing the mat-subgrade natural frequency.

Thesis advisor(s): Shin, Young S

The setting of alarm levels plays a vital role in a machinery condition monitoring and diagnostic system. In this research, two approaches to setting vibration alarm levels using vibration signals produced by fire pumps are presented in the time and frequency domains. In the time domain, the cross peak analysis (CPA) is proposed to extract the dominate peak points. The distribution of these cross peak points is found to have a lognormal distribution and can be normalized to a Normal distribution in the VdB domain. The computed microns + 2 Sigma value in the VdB domain is suggested for use as the alarm level. In the frequency domain, the 1/1 octave band analysis (OBA) is introduced. Three artificial fault simulations are conducted to compare the 1/1 octave band method with the broadband method. The results show that the 1/1 octave band method is more sensitive to the changes in VdB level than the broadband method. The computer programs to perform these two analyses are written using MATLAB. Examples of the use of these programs are included in this report. 1/1 Octave band analysis, Alarm level, Condition monitoring diagnostics, Cross peak analysis, Fire pump, Vibration.

12 p. : ill. ; 25 cm. trade catalogs.

The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers have been discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the stator. The use of piezoelectric pushers may provide similar degrees of effectiveness in light, compact packages. Tests are currently being conducted with piezoelectric pusher-based active vibration control. Results from tests performed on NASA test rigs as preliminary verification of the related theory are presented.

The setting of alarm levels plays a vital role in a machinery condition monitoring and diagnostic system. In this research, two approaches to setting vibration alarm levels using vibration signals produced by fire pumps are presented in the time and frequency domains. In the time domain, the cross peak analysis (CPA) is proposed to extract the dominate peak points. The distribution of these cross peak points is found to have a lognormal distribution and can be normalized to a Normal distribution in the VdB domain. The computed microns + 2 Sigma value in the VdB domain is suggested for use as the alarm level. In the frequency domain, the 1/1 octave band analysis (OBA) is introduced. Three artificial fault simulations are conducted to compare the 1/1 octave band method with the broadband method. The results show that the 1/1 octave band method is more sensitive to the changes in VdB level than the broadband method. The computer programs to perform these two analyses are written using MATLAB. Examples of the use of these programs are included in this report

This report describes the current status of a research project whose aim is to develop a hydrostatic bearing, for rotating machinery, whose dynamic characteristics may be tuned during operation of the machine. The purpose of this is to enable the operator to exercise some control over machine critical speeds and vibrations. A computer program has been written which will predict both the static and dynamic characteristics of a hydrostatic bearing. The program allows for the presence of accumulators linked to the hydrostatic bearing recesses via flow restrictors. Output from the computer program has been used as input data to a second computer program which calculates machine vibration amplitude variation with running speed. Theoretical machine characteristics obtained in this way have been used to aid the design of a test rig which will be used to examine the practical performance of the new bearing type being developed.

This report describes work carried out with the aim of developing a combined hydrostatic and squeeze-film bearing, for rotating machinery, whose dynamic characteristics may be tuned during operation of the machine. The purpose of this is to enable the operator to exercise control over machine critical speeds and vibrations. A computer program has been written to predict the characteristics of the bearing type, the program allows for the presence of accumulators linked to the bearing oil film whose purpose is to modify the bearing dynamic characteristics. A test rig has been designed and built, based on a General Electric TF34 turbofan engine, and both theoretical and experimental results confirm that a substantial shift in critical speed is effected by using the bearing, and that system vibration and force transmissibility may be reduced substantially when compared with the performance of conventional squeeze film bearings and journal bearings. Keywords: Vibration, Rotors.

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Food and Agriculture Section Name: Agricultural Tractors and Power Tillers (FAD 11) Designator of Legally Binding Document: IS 13548 Title of Legally Binding Document: Agricultural Wheeled Tractors and Field Machinery - Measurement of Whole-body Vibration of the Operator Number of Amendments: Equivalence: ISO 5008 Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda

Symposium topics include: An Integrated Gear System Dynamics Analysis over a Broad Frequency Range; Coupled Torsional-flexural Vibration of a Geared Shaft System Using Finite Element Analysis; Influence of an Axial Torque on the Dynamic Behavior of Rotors in Bending; Sensitivity Analysis of the Locations of the Balancing Planes of an Unbalanced Rotor-Bearing System using Dynamic Condensation Technique; Structural Damage Detection by the System Identification Technique; Time Domain Modal Analysis of a Slotted Cylindrical Shell; Application of the Ibrahim Time Domain (ITD) Algorithm to LANDSAT Transient Responses; Identification Matrix and Convergence of Parameters in Off-line System Identification; Model Evaluation of Spinal Injury Likelihood for Various Ejection System Parameter Variations; Time Domain Mathematical Modeling of Elastic Instabilities and Large Elastic-plastic Deflections; Low Order Dynamic Models of Indian Remote Sensing Satellite; A Direct Method for Estimating Lower and Upper Bounds of the Fundamental Frequency; and Approximating Dynamic Response in Small Arrays using Polynomial Parameterizations and Response Surface Methodology.

The development of a novel vibration isolator test facility is described. It is used to measure the dynamic properties of vibration isolators commonly used in maritime and industrial machinery applications. The vibration isolator test facility is capable of measuring the four pole parameters over the frequency range from 5 Hz to 2 kHz, static load range from 1 to 30 kN, and temperature range from 6 to 60 C. In order to demonstrate the usefulness of the facility, experimental data for three commercial asymmetrical vibration isolators used for maritime applications are presented. Their four pole parameters and effectiveness are compared.

The development of a novel vibration isolator test facility is described. It is used to measure the dynamic properties of vibration isolators commonly used in maritime and industrial machinery applications. The vibration isolator test facility is capable of measuring the four pole parameters over the frequency range from 5 Hz to 2 kHz, static load range from 1 to 30 kN, and temperature range from 6 to 60 C. In order to demonstrate the usefulness of the facility, experimental data for three commercial asymmetrical vibration isolators used for maritime applications are presented. Their four pole parameters and effectiveness are compared.

The development of a novel vibration isolator test facility is described. It is used to measure the dynamic properties of vibration isolators commonly used in maritime and industrial machinery applications. The vibration isolator test facility is capable of measuring the four pole parameters over the frequency range from 5 Hz to 2 kHz, static load range from 1 to 30 kN, and temperature range from 6 to 60 C. In order to demonstrate the usefulness of the facility, experimental data for three commercial asymmetrical vibration isolators used for maritime applications are presented. Their four pole parameters and effectiveness are compared.

Mechanical vibration analysis affords a reliable means to selectively identify specific machinery faults. As such, it plays a key role in diagnostic work on individual units and in progressive maintenance monitoring programs where substantial diagnostic and prognostic capabilities are considered essential. A physical machinery diagnostics model was developed that was designed to incorporate some of the more common machinery faults found in rotating machinery relating to shaft, bearing, gear, and alignment defects. The results of spectral analysis techniques used to detect these simulated faults are displayed and discussed, with special emphasis on gear train diagnostics. Also included are a description of one of the current U.S. Navy machinery vibration monitoring programs, and an initial study regarding a proposed technique for providing a graphic display of gear faults. Keywords: Vibrations, Signal analysis, Machinery diagnostics, Theses. (MJM)

Vibrational analysis of rotating machinery is able to identify a large number of system ills. Shaft bow, shaft unbalance and coupling misalignments make up the major portion of the observed vibrational frequency spectra of rotating machinery. These vibrational spectra can be used to determine the type of rotating system abnormality, the degree of misalignment and the rate of alignment degradation. The proper joining of rotating machinery is a critical issue with high power and a high speed equipments. Couplings used to join machinery have a broad spectrum of characteristics and specific purposes. Couplings are used to compensate for axial, lateral and angular misalignments. In addition, couplings may exhibit constant or non-constant input versus output speed relationships. The importance of mating a driving and driven piece of equipment with the properly designed coupling is paramount. In the following report the author discusses numerous types of couplings, the behavioral characteristics of couplings and the considerations which must be taken into account when selecting a coupling for a rotating system. The analysis which follows list the various alignment discrepancies which can be detected by vibrational analysis and the requirements for non-constant and constant velocity characteristics of couplings. In addition, numerous types of couplings are catalogued and discussed. Theses. (FR)

Advanced condition monitoring systems use pattern recognition and automated reasoning on features extracted from sensor data to assess the current health of a component. This paper will evaluate pattern recognition techniques for classifying the "stage of fault" using transitional failure data for commercial grade gearboxes. Features will be extracted from accelerometer data obtained on the Mechanical Diagnostic Testbed (MDTB) at Penn State Applied Research Lab. The ARL CBM Features toolbox, a MATLAB-based toolbox containing most of the traditional HUMS features and several novel features, will be used to perform feature extraction. Several classifiers and training methods will be evaluated, as well as the effect of using different dimension-reduction techniques on classification. The results obtained using the transitional failure data sets will contribute to enhanced health monitoring techniques and improved machinery health prognostic estimates.

The success or failure of active vibration control is determined by the availability of suitable actuators, modeling of the entire system including all active elements, positioning of the actuators and sensors, and implementation of problem-adapted control concepts. All of these topics are outlined and their special problems are discussed in detail. Special attention is given to efficient modeling of systems, especially for considering the active elements. Finally, design methods for and the application of active vibration control on rotating machinery are demonstrated by several real applications.

Thesis advisor, Young S. Shin

Title from cover

Partial contents: Multiple tests concept for improved validation of large space structure mathematical models; Algorithms and application of a new multi-input-multi-ouput modal parameter identification method; Modal parameter identification using adaptive digital filters; SAFE/DAE (Solar Array Flight Experiment Dynamics Augmentation Experiment): Modal test in space; Random variation of modal frequencies experiments and analysis; Structural degradation of impacted graphite/expoxy laminates; Updating rail impact test methods; Prediction of natural frequencies of flexible shaft-disc system; Implementation of action force control for robots subject to dynamic loading; Force magnitude and angular velocity fluctuation reduction in a spring-restrained; flexibility- supported four-bar mechanical linkage; Blade damping measurements in a spin rig with nozzle passing excitation simulated by electromagnets; New approach for gearbox modelling in-finite element analyses of torsional vibration of gear- branched propulsion systems; Temperature shift considerations for damping materials; Prediction of Metal Fatigue using Miner rule; Optimizing aerospace structures subjected to random vibration and fatigue constraints; Evaluation of vibration specifications for static and dynamic material allowables; and Supersonic flow induced cavity acoustics.

9 p. : 28 cm

Contents: Experimental Investigation of Controlling Vibrations using Multi-Unit Impact Dampers; An Experimental Hybrid Model for a Bilinear Hysteretic System; Measurement and Analysis of Platform Damping in Advanced Turbine Blade Response; Vibration Damping Treatment for High Temperature Gas Turbine Applications; Experimental Measurement of Material Damping using Digital Test Equipment; Electronic Damping of a Large Optical Bench; Measurement of Structural Damping Using the Random Decrement Technique; Damped Pneumatic Spring as Shock Isolator-Generalized Analysis and Design Procedure; Analytical and Experimental Investigation of Rotating Blade Response Due to Nozzle Passing Frequency Excitation; Prediction of Critical Speeds, Unbalance and Nonsynchronous Forced Response of Rotors; Unbalance Response of a Single Mass Rotor Mounted on Dissimilar Hydrodynamic Bearings; Nonlinear Coupling Responses to Variable Frequency Excitations; Simple Approximate Models for a Class of Structures; Source Signature Recovery in Reverberant Structures; and Comparison of Statistical Energy Analysis and Finite Element Analysis Vibration Prediction with Experimental Results.

Contents: Experimental Investigation of Controlling Vibrations using Multi-Unit Impact Dampers; An Experimental Hybrid Model for a Bilinear Hysteretic System; Measurement and Analysis of Platform Damping in Advanced Turbine Blade Response; Vibration Damping Treatment for High Temperature Gas Turbine Applications; Experimental Measurement of Material Damping using Digital Test Equipment; Electronic Damping of a Large Optical Bench; Measurement of Structural Damping Using the Random Decrement Technique; Damped Pneumatic Spring as Shock Isolator-Generalized Analysis and Design Procedure; Analytical and Experimental Investigation of Rotating Blade Response Due to Nozzle Passing Frequency Excitation; Prediction of Critical Speeds, Unbalance and Nonsynchronous Forced Response of Rotors; Unbalance Response of a Single Mass Rotor Mounted on Dissimilar Hydrodynamic Bearings; Nonlinear Coupling Responses to Variable Frequency Excitations; Simple Approximate Models for a Class of Structures; Source Signature Recovery in Reverberant Structures; and Comparison of Statistical Energy Analysis and Finite Element Analysis Vibration Prediction with Experimental Results.

32 p. : ill. ; 19 cm. trade catalogs.

32 p. : ill. ; 19 cm. trade catalogs.

Practical Machinery Vibration Analysis And Predictive Maintenance Paresh Girdhar

Practical Machinery Vibration Analysis And Predictive Maintenance Paresh Girdhar

This report describes the current status of a research project whose aim is to develop a hydrostatic bearing, for rotating machinery, whose dynamic characteristics may be tuned during operation of the machine. The purpose of this is to enable the operator to exercise some control over machine critical speeds and vibrations. A computer program has been written which will predict both the static and dynamic characteristics of a hydrostatic bearing. The program allows for the presence of accumulators linked to the hydrostatic bearing recessess via flow restrictors. Output from the computer program has been used as input data to a second computer program which calculates machine vibration amplitude variation running speed. Theoretical machine characteristics obtained in this way have been used to aid the design of a test rig which will be used to examine the practical performance of the new bearing type being developed.

This report describes the current status of a research project whose aim is to develop a hydrostatic bearing, for rotating machinery, whose dynamic characteristics may be tuned during operation of the machine. The purpose of this is to enable the operator to exercise some control over machine critical speeds and vibrations. A computer program has been written which will predict both the static and dynamic characteristics of a hydrostatic bearing. The program allows for the presence of accumulators linked to the hydrostatic bearing recessess via flow restrictors. Output from the computer program has been used as input data to a second computer program which calculates machine vibration amplitude variation running speed. Theoretical machine characteristics obtained in this way have been used to aid the design of a test rig which will be used to examine the practical performance of the new bearing type being developed.

Thesis (N.E. and M.S. in M.E.)--Massachusetts Institute of Technology, 1964

Thesis (N.E. and M.S. in M.E.)--Massachusetts Institute of Technology, 1964

Practical Machinery Vibration Analysis and Predictive Maintenance by Paresh Girdhar

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Committee Designation: MED 7 Designator of Legally Binding Document: IS/ISO 7096 : 2020 Title of Legally Binding Document: Earth-Moving Machinery — Laboratory Evaluation of Operator Seat Vibration Number of Amendments: 0 Status: Active Additional Info: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru

The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers was discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the stator. The use of piezoelectric pushers may provide similar degrees of effectiveness in light, compact packages. Analyses are contained which extend quadratic regulator, pole placement and derivative feedback control methods to the prescribed displacement character of piezoelectric pushers. The structural stiffness of the pusher is also included in the theory. Tests are currently being conducted at NASA Lewis Research Center with piezoelectric pusher-based active vibration control. Results performed on the NASA test rig as preliminary verification of the related theory are presented.

The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers was discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the stator. The use of piezoelectric pushers may provide similar degrees of effectiveness in light, compact packages. Analyses are contained which extend quadratic regulator, pole placement and derivative feedback control methods to the prescribed displacement character of piezoelectric pushers. The structural stiffness of the pusher is also included in the theory. Tests are currently being conducted at NASA Lewis Research Center with piezoelectric pusher-based active vibration control. Results performed on the NASA test rig as preliminary verification of the related theory are presented.

Thesis (M.S. in Mechanical Engineering and Naval Engineer) Massachusetts Institute of Technology, May 1988