Experimental and analytical evaluation of dynamic load and vibration of a 2240-kW (3000-hp) rotorcraft transmission

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Published by National Aeronautics and Space Administration, For sale by the National Technical Information Service in [Washington, DC, [Springfield, Va .

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  • Helicopters -- Control systems.

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StatementFred K. Choy, Dennis P. Townsend, and Fred B. Oswald.
SeriesNASA technical memorandum -- 88975.
ContributionsTownsend, Dennis P., Oswald, Fred B., United States. National Aeronautics and Space Administration.
The Physical Object
Pagination1 v.
ID Numbers
Open LibraryOL14661688M

Download Experimental and analytical evaluation of dynamic load and vibration of a 2240-kW (3000-hp) rotorcraft transmission

Experimental and Analytical Evaluation of Dynamic Load Vibration of a kW (hp) Rotorcraft Transmission by FRED K. CHOY Department of Mechanical Engineering, University of Akron, Akron, OHU.S.A.

and DENNIS P. TOWNSEND and FRED B. OSWALD National Aeronautics and Space Administration, Lewis Research Center, Cleveland, OHU.S.A. ABSTRACT: A dynamic Cited by: 5. A dynamic analysis of a kW (hp) helicopter planetary system is presented.

Results from both analytical and experimental studies show good correlation in gear-tooth loads. A Experimental and analytical evaluation of dynamic load and vibration of a 2240-kW book study indicates that the mesh damping ratio has a significant effect on maximum gear-tooth load, stress, and vibration.

A dynamic analysis of a kW (hp) helicopter planetary system is presented. Results from both analytical and experimental studies show good correlation in gear-tooth loads. A parametric study indicates that the mesh damping ratio has a significant effect on maximum gear tooth load, stress, and vibration.

Get this from a library. Experimental and analytical evaluation of dynamic load and vibration of a kW (hp) rotorcraft transmission. [Fred K Choy; Dennis P Townsend; Fred B Oswald; United States.

National Aeronautics and Space Administration.]. mapping system in dynamic tests of corrugated boxes and to perform a detailed analysis of the mechanical behavior of a corrugated box packaging system.

The analysis will include the estimation of the dynamic behavior of the packaging. During the investigation, analysis tools such as pressure mapping methods and mathematical modeling were used.

The gearbox vibrations were obtained from both numerical simulation and experimental studies using a gear noise test rig. In addition, the noise generated by the gearbox vibrations was recorded. In this paper, we propose a dynamic vibration absorber (DVA) with an air damper consisting of a piston and a cylinder.

First, it will be shown that the air damper can conveniently be represented by the Maxwell model where a spring element and a dashpot are connected in by: effect of the axial load on the maximum deformations, vibration periods, strain rates, and contributing modes in the dynamic response were study by comparing the beam results with the column results tested in the same blast shots.


ME Department of Mechanical Engineering National Institute of Technology Rourkela A dynamic analysis of a kW (hp) helicopter planetary system is presented. Results from both analytical and experimental studies show good correlation in gear-tooth loads.

The calibrated model, which is adjusted to reflect the real in-situ condition and performance of the bridge, will then be used for the purpose of realistic load rating. This paper starts by reviewing the limitations of the current analytical and empirical methods and provides an in-depth explanation of the vibration-based method for load by: 3.

Two experimental methods can be applied to determine experimentally, in situ or in laboratory, the dynamic characteristics of a structure, as natural frequency and the damping ratio.

The first method consists in determining the structural response, in terms of displacement or acceleration, at free vibrations produced by a dynamic load, like. In this paper, dynamic model of two stage power branch double wide helical gear planetary drive system based on complex, in-depth study of the natural vibration characteristic.

Starting from the first star and second planetary gear around the sun wheel non equidistant arrangement in the respective gear train, calculating modal analysis of characteristics of the system, so as to understand the Author: Xue Zeng Zhao, Xi Gui Wang, Yong Mei Wang.

Parameters optimization and performance evaluation for the novel inerter-based dynamic vibration absorbers with negative stiffness select article A methodology for measurement-system design combining information from static and dynamic excitations for bridge load testing select article Experimental and numerical investigation of noise.

Substructure Methods in Vibration R. Craig, Jr. Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX Cited by: VIBRATION ANALYSIS OF MOVING LOAD PROBLEMS WITH PARTICULAR EMPHASIS ON ANALYTICAL AND SEMI- Moving loads, Induced vibrations, Dynamic analysis, Railway dynamics.

ABSTRACT With the evolution of the computational power, there is a tendency to overlook analytical and Lisowski S., (). Analytical evaluation of track response in the. Experimental and Analytical Studies on Reinforced Concrete Buildings with Seismically Vulnerable Beam- Column Joints Exploiting Nonlinear Behavior in Structural Dynamics Exploring Classical Greek Construction Problems with Interactive Geometry Software.

The system consists of two input modules and one main module, with a total speed reduction of The main module consists of a tooth sun gear that drives five tooth planetary gears, with the carrier splined to the output rotor shaft. The stationary ring gear has teeth.

the behaviour of a viscoelastic material subjected to an oscillatory load, one needs to formulate the theory based on oscillatory stresses and strains. Oscillatory Stress Consider a dynamic load of the form (t) o cos(t) () where o is the stress amplitude and is File Size: 83KB. to the vibrational load of the structure is known as vibrational fatigue and has been a subject of several research studies in recent years.

Vibrational fatigue can be studied for harmonic or random vibration loads. In both cases the stress load leading to the fatigue failure occurs due to the structure’s own dynamic response.

The proposed book will offer comprehensive and versatile methodologies and recommendations on how to determine dynamic characteristics of typical micro- and opto-electronic structural elements (printed circuit boards, solder joints, heavy devices, etc.) and how to design a viable and reliable structure that would be able to withstand high-level dynamic loading.

ARL-RP Mar S Army Research LaboratoryU. A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison.

by Robert P Author: Robert P Thornburgh, Andrew R Kreshock, Matthew L Wilbur. dynamic load is transformed to an ESL set. The ESL set is made to generate the identical displacement field with the one from the dynamic load at an arbitrary time [].

The displacement field under the dynamic load can be expressed by the modal analysis in the vibration theory. vibration excitation. The goal of modal analysis in structural mechanics is to determine the natural mode shapes and frequencies of an object or structure during free vibration.

The various research papers studied are based on evaluation of specific properties or characteristics of vibration of beams by various techniques. ‟sCited by: 1. In engineering, a large number of structures may be modeled as cantilevers.

Due to their intrinsic characteristics, some of these structures are sensitive to dynamic actions. Gusts of wind are dynamic excitations for which the fundamental frequency of vibration is an important factor when calculating the structural response. Modeling the effects of the axial force on the natural frequencies of Cited by: 9.

WITH EULER-BERNOULLI BEAM THEORY; MECHANICAL EFFECTS DUE TO PULSE WIDTH VARIATION OF SHOCK INPUTS; AND EVALUATION OF SHOCK RESPONSE OF A MIXED FLOW FAN A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Mechanical Engineering.

International Journal ofRotating MachineryVol. 1, No.pp. Reprints available directly from the publisher Photocopying permitted by license only (C) OPA(Overseas Publishers Association) AmsterdamB.V.

Published underlicense by Gordonand Breach Science Publishers SA Printed in Singapore Vibrational Diagnostics of Rotating Machinery Malfunctions. Dynamics & Vibration Dynamics & Vibration. Research. Dynamics and vibrations are integral parts of understanding many physical systems and technologies - everything from MEMS sensors and devices to air and space structures to the development of novel materials.

We use advanced computation and measurement techniques to create accurate. The paper presents a systematic procedure and details of the use of experimental and analytical modal analysis technique for structural dynamic evaluation processes of a vertical machining centre. The main results deal with assessment of the mode shape of the different components of the vertical machining centre.

The simplified experimental modal analysis of different components of milling Cited by: used technique in condition based maintenance and rely a lot on instrumentation Machine vibrations stack a lot of information about the condition of a machine.

Measurement and analysis of the vibration response gives a lot of information with relevance to fault conditions in different types of machines (Khwaja, Gupta, & Kumar, ). Calculate the analytical value of the natural frequency and compare with the experimental value APPARATUS 1.

Test rig 2. Frequency analyzer 3. Function/Waveform generator THEORY ON VIBRATION Mechanical Vibration Mechanical Vibration is defined as the motion of a system (a particle or a body) which oscillates about its stable equilibrium Size: KB.

Theoretical and Experimental Free Vibration Analysis of a Loaded Curved Beam With Moving Boundaries: Vibration Analysis of Beam With Moving Boundaries: /IJMMME The present article theoretically and experimentally investigates free vibration characteristics of generalized curved beams with moving boundaries.

TheAuthor: Sushanta Ghuku, Kashi Nath Saha. Natural Period of Vibration 16 Dynamic Load Factor (DLF) 17 Dynamic Response to Suddenly Applied Rectangular Load 18 Dynamic Response to Suddenly Applied Triangular Load 18 Accurate Analytical Method of Dynamic Analysis of.

The mechanical dynamic behavior of a pulp, board, paper or tissue machine is a limiting factor for the machine's capacity. Vibrations in machine equipment constitute a safety hazard, and will cause severe. ISO provides methodology for the evaluation of results from dynamic tests and investigations on bridges and viaducts.

It complements the procedure for conducting the tests as given in ISO and considers-- the objectives of the dynamic tests,-- the techniques for data analysis and system identification,-- the modelling of the bridge, and-- evaluation of the measured Manufacturer: Multiple.

Distributed through American National Standards Institute. Rezaee, M., Aly, A.M. (), “Vibration Control in Wind Turbines to Achieve Desired System-Level Performance under Single and Multiple Hazard Loadings,” Structural Control and Health Monitoring, DOI/stc Aly, A.M., Chokwitthaya, C., Poche, R.

(), “Retrofitting Building Roofs with Aerodynamic Features and Solar Panels to Reduce Hurricane Damage and Enhance Eco-Friendly.

DYNAMIC CHARACTERIZATION AND VIBRATION SERVICEABILITY ASSESSMENT OF A HIGHLY TRAFFICKED, LIVELY PEDESTRIAN BRIDGE A Thesis Presented to the faculty of the School of Engineering and Applied Science at University of Virginia in partial fulfillment of the requirements for the degree Master of Science by SALMAN USMANI May Dynamic & Vibration Analysis Services Modal Analysis.

If loads change with time, then one needs to be concerned about the resonance frequencies of your product or structure. A modal analysis is used to calculate the resonance frequencies, corresponding shapes and mass participation. load can be considered static, quasi-static, or dynamic.

This characteristic time is the fundamental period of free vibration of the system. Dynamic Load Magnification factor (DLF) is the ratio of the maximum dynamic force experienced by the system and the maximum applied load.

The small period of vibration results in a small DLF. RE: Conversion of Dynamic Load to a Quasi-Static Load GregLocock (Automotive) 13 Nov 07 The way I'd use that data is use a 1DOF model of the wheel/spring/shock to derive a maximum force at the contact patch, and then apply that force to a static FEA model to get some idea of maximum stresses.

Mechanical Vibrations: Theory and Application to Structural Dynamics, Third Edition is a comprehensively updated new edition of the popular textbook. It presents the theory of vibrations in the context of structural analysis and covers applications in mechanical and aerospace engineering.

Key features include: A systematic approach to dynamic reduction and substructuring, based on duality.Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium word comes from Latin vibrationem ("shaking, brandishing").

The oscillations may be periodic, such as the motion of a pendulum—or random, such as the movement of a tire on a gravel road. Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or.load, body load, distributed load, etc.

Dynamic stress and strain at critical locations if the component is best represented as a continuous system Response limit criteria, such as yield stress, ultimate stress, fatigue, or loss of clearance Each of the response parameters should be given in terms of frequency response function, powerFile Size: 1MB.

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