Optimization of Tooth Bending Fatigue Characteristics of Spur Gear Pairs Using a Gear Dynamics-Based Approach

2015 ◽  
Author(s):  
Yalın Öztürk ◽  
Ender Ciğeroğlu ◽  
H. Nevzat Özgüven
Keyword(s):  
Fatigue Life ◽  
Gear Tooth ◽  
Spur Gear ◽  
Bending Fatigue ◽  
Gear Dynamics ◽  
Optimization Study ◽  
Fatigue Life Estimation ◽  
Fatigue Characteristics ◽  
Profile Optimization ◽  
Operational Range

A gear tooth profile optimization study is performed with the target being defined as the maximization of tooth bending fatigue life for a selected operational range, where the operating torque and speed ranges are defined along with their corresponding durations. For this purpose, a nonlinear lumped gear dynamics model is combined with the S/N curve of the gear material in order to estimate tooth bending fatigue life of the spur gear pair. The differences between the predicted lives of the optimally modified and non-modified gear pairs are presented based on example spur gear pairs. The proposed tooth bending fatigue life estimation is compared with the standard AGMA procedure.

Numerical model for bending fatigue life estimation of carburized spur gears with consideration of the adjacent tooth effect

2021 ◽  
Vol 153 ◽  
pp. 106515
Author(s):  
Krešimir Vučković ◽  
Ivan Čular ◽  
Robert Mašović ◽  
Ivica Galić ◽  
Dragan Žeželj
Keyword(s):  
Fatigue Life ◽  
Numerical Model ◽  
Spur Gears ◽  
Bending Fatigue ◽  
Life Estimation ◽  
Adjacent Tooth ◽  
Fatigue Life Estimation

Explicit Parametric Method for Optimal Spur Gear Tooth Profile Definition

2013 ◽  
Vol 633 ◽  
pp. 87-102 ◽  
Author(s):  
Ivana Atanasovska ◽  
Radivoje Mitrovic ◽  
Dejan Momcilovic
Keyword(s):  
Gear Tooth ◽  
Load Capacity ◽  
Parametric Method ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Element Analysis ◽  
Engineering Research ◽  
Profile Optimization ◽  
Current Engineering

The gear tooth profile has an immense effect on the main operating parameters of gear pairs (load capacity, working life, efficiency, vibrations, etc). In current engineering research and practice, there is a strong need to develop methods for tooth profile optimization. In this paper a new method for selecting the optimal tooth profile parameters of spur gears is described. This method has been named the Explicit Parametric Method (EPM). The addendum modification coefficient, radius of root curvature, and pressure angle of the basic rack for cylindrical gears, have been identified as the main tooth profile parameters of spur gears. Therefore, the EPM selects the optimal values for these three tooth profile parameters. Special attention has been paid to develop a method of adjustment for the particular working conditions and explicit optimization requirements. The EPM for optimal tooth profile parameters of gears uses contact nonlinear Finite Element Analysis (FEA) for calculation of deformations and stresses of gear pairs, in addition to explicit comparative diagrams for optimal tooth profile parameter selection.

A Study on the Improvement of Durability of Gear Steel by Shot Peening

2006 ◽  
Vol 321-323 ◽  
pp. 662-665 ◽  
Author(s):  
Dong Sun Lee ◽  
Tae Hyung Kim ◽  
Jae Heon Lee ◽  
Tae Kun Lee ◽  
Seong Kyun Cheong
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Spur Gear ◽  
Sem Image ◽  
Gear Steel ◽  
Ball Velocity ◽  
Bending Fatigue Test ◽  
Fatigue Characteristics

In this paper the fatigue life of spur gear was investigated by changing the shot peening condition. From bending fatigue test depending on various shot peening intensity, fatigue characteristics were investigated. The causes of reduction in fatigue life were analyzed by observing the surface of gear with Scanning Electron Microscope(SEM), and impact of residual stress to fatigue characteristics was identified by measuring compressive residual stress depending peening intensity by depth. The results show that the optimum shot ball velocity is 65 m/s and optimum peening time is 8 minutes. From SEM image, the micro-crack was observed at the surface in case of over peening. This seems to be the factor which reduces fatigue life by decreasing compressive residual stress of surface.

Estimation of Fatigue Life of Materials with Out-of-Parallel Fatigue Characteristics under Block Loading

2012 ◽  
Vol 726 ◽  
pp. 181-188 ◽  
Author(s):  
Marta Kurek ◽  
Tadeusz Łagoda
Keyword(s):  
Fatigue Life ◽  
Alloy Steel ◽  
Experimental Results ◽  
High Alloy ◽  
High Alloy Steel ◽  
Life Estimation ◽  
Block Loading ◽  
Fatigue Life Estimation ◽  
Fatigue Characteristics

The paper presents the algorithm of fatigue life estimation for materials with out-of-parallel fatigue characteristics under block loading. Brass CuZn40Pb2, medium-alloy steel 30CrNiMo8 and high-alloy steel 35NCD16 belong to such materials. Brass CuZn40Pb2 was used for analysis. The experimental results were compared with those calculated according to the assumed model, and satisfactory results were obtained.

Fatigue Life Estimation under Cyclic Loading Including Out-of-Parallelism of the Characteristics

2011 ◽  
Vol 104 ◽  
pp. 125-132 ◽  
Author(s):  
Marta Kurek ◽  
Tadeusz Łagoda
Keyword(s):  
Fatigue Life ◽  
Alloy Steel ◽  
Shear Stresses ◽  
Pure Bending ◽  
High Alloy ◽  
High Alloy Steel ◽  
Fatigue Life Estimation ◽  
Fatigue Characteristics ◽  
Fatigue Criterion ◽  
Normal And Shear Stresses

The paper presents an algorithm of fatigue life determination for materials with no parallel fatigue characteristics under pure bending and pure torsion. The presented model uses the iteration method, and the applied fatigue criterion is function of the ratio of normal and shear stresses coming from bending and torsion, respectively. Three materials were applied for analysis: CuZn40Pb2 brass, 30CrNiMo8 medium-alloy steel and 35NCD16 high-alloy steel.

Bending Fatigue Characteristics of WC-βt-Co Alloys

2009 ◽  
Vol 407-408 ◽  
pp. 15-18
Author(s):  
Kusuhiko Sakagami ◽  
Shinichi Kouno ◽  
Tsutomu Yamamoto
Keyword(s):  
Fatigue Life ◽  
Cutting Tools ◽  
High Stress ◽  
Coarse Grained ◽  
Stress Range ◽  
Bending Fatigue ◽  
Fine Grained ◽  
Large Gradient ◽  
Fatigue Characteristics ◽  
Co Alloys

WC-βt-Co alloys have been widely applied to cutting tools because they are superior to WC-Co alloys in oxidation, plastic deformation and adhesion resistances. In this study, the effects of HIP treatment, WC grain size and content of βt phase on bending fatigue characteristics were investigated for fine and coarse-grained WC-6.7mass%βt-10.4mass%Co alloys （6.7βt(F) and 6.7βt(C) alloys） and fine-grained WC-20mass%βt-11.3mass%Co alloy (20βt(F) alloy) by comparing with the case of fine-grained WC-10mass%Co alloy（10Co(F) alloy） without βt phase. The results obtained were as follows: 1) The bending fatigue life of HIP-ed 6.7βt(F) alloy was longer than that of normally sintered 6.7βt(F) alloy. The S-N curve of HIP-ed alloy showed a small gradient in a high stress range and a large gradient in a low stress range. 2) The fatigue life of HIP-ed 6.7βt(F) alloy remarkably decreased in the high stress range, but slightly decreased in the low stress range, compared with that of 10Co(F) alloy. 3) The fatigue life of HIP-ed 6.7βt(C) alloy was superior in all the stress range, compared with that of HIP-ed 6.7βt(F) alloy. 4) The fatigue life of HIP-ed 20βt(F) alloy was shorter than that of 6.7βt(F) alloy in all the stress range．The above-mentioned results were mainly discussed relating to the fatigue fracture origins such as pore, Co pool, agglomerate of βt grains, etc.

Tooth Profile Modifications for Optimum Dynamic Load in Spur Gears Based on Pseudo-Interference Stiffness Estimation Method

2005 ◽  
Author(s):  
Monsak Pimsarn ◽  
Kazem Kazerounian
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Estimation Method ◽  
Spur Gear ◽  
Rigid Body Dynamics ◽  
Gear System ◽  
Hertzian Contact ◽  
Bending Fatigue ◽  
Gear Mesh ◽  
Hertzian Contact Stress

A systematic methodology combining optimization, three dimensional analytical rigid body dynamics and a novel method, namely, Pseudo-Interference Stiffness Estimation method (PISE) [1]- [2], is proposed to dramatically reduce gear design time and improve the spur gear system dynamic performance. The main aim of this methodology is to search for the pro les of tooth crowning and shaving that eventually lead to the optimum dynamic tooth load in the gear mesh. An example of the detailed design study is numerically investigated. The results show that the dynamic tooth load can be reduced to up to 50 percent of its original value. However, this reduction is only valid at the operating ranges of the design load and design speed. It is also found that the effect of pro le modi cation on the dynamic response of the gear system was mostly observed to be a reduction in the peak dynamic tooth load at the resonance speed. Later, the investigation of gear tooth durability was conducted to validate an improvement of gear life. The rating factors given in AGMA publication, Hertzian contact stress, bending fatigue stress, ash temperature and PV index are employed in gear durability determination. The results show that, with the reduction of 50 percent in dynamic tooth load, the reductions in PV index, bending fatigue, Hertzian contact stress, and ash temperature can be achieved up to 64, 58, 28 and 39 percent, respectively.

An Integrated Approach to Wind Turbine Fatigue Analysis

1997 ◽  
Vol 119 (3) ◽  
pp. 242-247
Author(s):  
D. J. Laino ◽  
A. C. Hansen
Keyword(s):  
Fatigue Life ◽  
Wind Turbine ◽  
Integrated Approach ◽  
Phase Iii ◽  
Normal Operation ◽  
Material Fatigue ◽  
Fatigue Life Estimation ◽  
First Results ◽  
Fatigue Characteristics ◽  
Ongoing Project

The wind turbine dynamics codes YawDyn and ADAMS have been interfaced with the LIFE2 code for fatigue life estimation via a new interface program, Dyn2LIFE. This work is sponsored by the National Renewable Energy Laboratory (NREL) with the intent of making it straightforward and practical for wind turbine designers to determine those aspects of their design and wind environment that will cause the most fatigue damage. Several parameters suspected of affecting turbine fatigue life are investigated through a model of the NREL Phase III Combined Experiment Rotor. This study proved the Dyn2LIFE code useful in creating LIFE2 input from YawDyn and ADAMS output, and also revealed some areas of possible expansion and improvement. Results from this study of a steel blade root suggest changes affecting the normal operation of the turbine alter fatigue life more than rare, high load events. Understanding how the material fatigue characteristics affect lifetime estimates is discussed in terms of the S-N curve utilized in this study. This paper presents the first results from an ongoing project. In the future, we plan to analyze a variety of turbine configurations to help identify those variables which may have the greatest influence on fatigue life.

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