Analysis of the Housing Vibration of a Rotorcraft Planetary Gear Using a Finite Element/Contact Mechanics Model

2017 ◽  
Author(s):  
Christopher G. Cooley ◽  
Adrian A. Hood
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Planetary Gear ◽  
Time Instant ◽  
Frequency Content ◽  
Contact Conditions ◽  
Gear Teeth ◽  
Mechanics Model ◽  
Parametric Studies ◽  
Frequency Components

This study investigates the planetary gear housing vibration for rotorcraft systems with equally spaced and diametrically opposed planets using a finite element/contact mechanics model. This approach permits accurate housing deflection calculations at each time instant that result from the changing contact conditions on all gear teeth and elastic deformations of each gear. Planetary gears with diametrically opposed planets have larger amplitude vibrations and more frequency content than those with equally spaced planets. Parametric studies show that although the frequency content does not change with changes in the system’s parameters, the amplitudes of response at these frequencies are meaningfully impacted. The frequency components of the acceleration spectra can have additional content when the planetary gear has manufacturing and assembly errors. Each error case results in different frequency content in the acceleration spectra. Understanding these housing vibrations is beneficial for interpreting measured accelerometer signals to detect and classify damage.

Prediction and Experimental Correlation of Tooth Root Strains in Spur Gear Pairs

2015 ◽  
Author(s):  
Xiang Dai ◽  
Christopher G. Cooley ◽  
Robert G. Parker
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Gear Tooth ◽  
Strain Curve ◽  
Spur Gear ◽  
Tooth Root ◽  
Contact Conditions ◽  
Tooth Contact ◽  
Mechanics Model ◽  
Large Amplitude Vibration

Spur gear tooth root strains are calculated using a finite element/contact mechanics formulation for varying gear speeds and applied torques. Extensive comparisons with experiments, including those from the literature and new ones, confirm that the finite element/contact mechanics formulation accurately predicts the quasi-static and dynamic tooth root strains. The finite element/contact mechanics model is used to investigate the features of the tooth root strain curves as the gears rotate kinematically and the tooth contact conditions change. Tooth profile modifications are shown to strongly affect the shape of the strain curve. At non-resonant speeds the dynamic tooth root strain curves have similar shapes as the quasi-static strain curves. At resonant speeds, however, the dynamic tooth root strain curves are drastically different because large amplitude vibration causes tooth contact loss.

scholarly journals Vibration Based Diagnosis for Planetary Gearboxes Using an Analytical Model

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Liu Hong ◽  
Yongzhi Qu ◽  
Yuegang Tan ◽  
Mingyao Liu ◽  
Zude Zhou
Keyword(s):  
Analytical Model ◽  
Planetary Gear ◽  
Diagnostic Techniques ◽  
Dynamic Simulations ◽  
Diagnostic Efficacy ◽  
Planetary Gearbox ◽  
Gear Teeth ◽  
Detection And Identification ◽  
Planetary Gear Sets ◽  
Frequency Components

The application of conventional vibration based diagnostic techniques to planetary gearboxes is a challenge because of the complexity of frequency components in the measured spectrum, which is the result of relative motions between the rotary planets and the fixed accelerometer. In practice, since the fault signatures are usually contaminated by noises and vibrations from other mechanical components of gearboxes, the diagnostic efficacy may further deteriorate. Thus, it is essential to develop a novel vibration based scheme to diagnose gear failures for planetary gearboxes. Following a brief literature review, the paper begins with the introduction of an analytical model of planetary gear-sets developed by the authors in previous works, which can predict the distinct behaviors of fault introduced sidebands. This analytical model is easy to implement because the only prerequisite information is the basic geometry of the planetary gear-set. Afterwards, an automated diagnostic scheme is proposed to cope with the challenges associated with the characteristic configuration of planetary gearboxes. The proposed vibration based scheme integrates the analytical model, a denoising algorithm, and frequency domain indicators into one synergistic system for the detection and identification of damaged gear teeth in planetary gearboxes. Its performance is validated with the dynamic simulations and the experimental data from a planetary gearbox test rig.

Effect of Crack Closure Parameter and Negative Triaxiality on Damage Growth in Upsetting Problem

2015 ◽  
Vol 784 ◽  
pp. 369-376 ◽  
Author(s):  
Manoj Kumar ◽  
P.M. Dixit
Keyword(s):  
Finite Element ◽  
Crack Closure ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Damage Growth ◽  
Mechanics Model ◽  
Finite Element Package ◽  
Parametric Studies ◽  
Correct Location

A Continuum Damage Mechanics model, that incorporates a crack closure parameter and a cut-off on negative triaxiality, is employed to simulate the damage growth in upsetting problem using the finite element package ABAQUS. Parametric studies are carried out to find the effect of the crack closure parameter and the cut-off. It is shown that the correct location of the maximum damage in upsetting problem (i.e., the location reported in the experimental literature) is predicted only if these parameters are incorporated.

scholarly journals Dynamic Analysis of Gear Pairs with the Effects of Stick-slip

2021 ◽  
Author(s):  
Chao Xun ◽  
He Dai
Keyword(s):  
Dynamic Analysis ◽  
Vibration Velocity ◽  
Sliding Velocity ◽  
Mesh Stiffness ◽  
Stick Slip ◽  
Gear Teeth ◽  
Tooth Surfaces ◽  
Parametric Studies ◽  
Frequency Components ◽  
Heavy Loads

Abstract A stick-slip dynamic model of a two-gear set is proposed. In this model, time-varying mesh stiffness, tooth separation, friction between the gear teeth surfaces and potential stick-slip are considered. Considering the contributions of the vibration velocity to the gear teeth sliding velocity, transition conditions between the stick state and slip state are revealed. Dynamic analysis shows that, when stick appears, the vibration amplitudes are dramatically increased, and tooth separation occurs. Additionally, stick also induces half-frequency components of the mesh frequency and causes chaos. Parametric studies show that heavy loads and rough tooth surfaces increase the probability of stick and increase the time of the stick state over a single mesh period. However, due to the complex nonlinearity, the existence of a certain relationship between the gear rotation speed and the stick time is not confirmed.

A Study of Gear Root Strains in a Multi-Stage Planetary Wind Turbine Gear Train Using a Three Dimensional Finite Element/Contact Mechanics Model and Experiments

2011 ◽  
Author(s):  
Phillip E. Prueter ◽  
Robert G. Parker ◽  
Frank Cunliffe
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Contact Mechanics ◽  
Three Dimensional ◽  
Gear Train ◽  
Mechanics Model ◽  
Multi Stage ◽  
Dimensional Finite Element ◽  
Advanced Analysis ◽  
Three Dimensional Finite Element

Wind energy has received a great deal of attention in recent years in part due to its minimal environmental impact and improving efficiency. Increasingly complex wind turbine gear train designs, well-known failures in gear train rolling element bearings, and the constant push to manufacture more reliable, longer lasting systems generate the need for more advanced analysis techniques. The objectives of this paper are to examine the mechanical design of an Orbital2 flexible pin multi-stage planetary wind turbine gear train using a three dimensional finite element/contact mechanics model and to compare to full system experiments. Root strain is calculated at multiple locations across the facewidth of ring gears from the computational model and compared to experimental data. Gear misalignment and carrier eccentricity are also considered. Design recommendations for improving load distribution across gear facewidths are also discussed.

Based on ANSYS Planetary Gear Ransmission Design Analysis

2011 ◽  
Vol 314-316 ◽  
pp. 1218-1221
Author(s):  
Hao Min Huang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Stress ◽  
Planetary Gear ◽  
Design Analysis ◽  
Ansys Software ◽  
Element Analysis ◽  
Planet Gear ◽  
Gear Contact ◽  
Transmission Gear

Conventional methods of design to be completed ordinary hydraulic transmission gear gearbox design, but for such a non-planet-rule entity, and the deformation of the planet-gear contact stress will have a great impact on the planet gear, it will be very difficult According to conventional design. In this paper, ANSYS software to the situation finite element analysis, the planetary gear to simulate modeling study.

scholarly journals A Finite Element Study on Compressive Resistance Degradation of Square and Circular Steel Braces under Axial Cyclic Loading

2021 ◽  
Vol 11 (13) ◽  
pp. 6094
Author(s):  
Hubdar Hussain ◽  
Xiangyu Gao ◽  
Anqi Shi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cyclic Loading ◽  
Slenderness Ratio ◽  
Hysteretic Behavior ◽  
Element Analysis ◽  
Section Shape ◽  
Axial Cyclic Loading ◽  
Global Buckling ◽  
Parametric Studies

In this study, detailed finite element analysis was conducted to examine the seismic performance of square and circular hollow steel braces under axial cyclic loading. Finite element models of braces were constructed using ABAQUS finite element analysis (FEA) software and validated with experimental results from previous papers to expand the specimen’s matrix. The influences of cross-section shape, slenderness ratio, and width/diameter-to-thickness ratio on hysteretic behavior and compressive-tensile strength degradation were studied. Simulation results of parametric studies show that both square and circular hollow braces have a better cyclic performance with smaller slenderness and width/diameter-to-thickness ratios, and their compressive-tensile resistances ratio significantly decreases from cycle to cycle after the occurrence of the global buckling of braces.

Sign in / Sign up

Export Citation Format

Share Document