Gear Tooth Bending Fatigue Life Prediction Using Integrated Computational Material Engineering

2017 ◽  
Author(s):  
Michael E. Oja ◽  
Carlos H. Wink ◽  
Nikhil Deo ◽  
Robert L. McDaniels ◽  
Robert G. Tryon ◽  
...  
Keyword(s):  
Gear Tooth ◽  
Fatigue Behavior ◽  
Computational Method ◽  
Vehicle Group ◽  
Cyclic Life ◽  
Bending Fatigue ◽  
Damage Models ◽  
Microstructural Damage ◽  
Single Tooth ◽  
Physical Testing

The paper presents a computational method to predict the cyclic life of gears subjected to single tooth bending fatigue, using VEXTEC’s VPS-MICRO® software. The project was a collaborative effort between Eaton - Vehicle Group and VEXTEC Corporation to replicate physical testing virtually, more specifically to virtually determine bending fatigue curves of gears made from different steels. VPS-MICRO is based on VEXTEC’s patented Virtual Life Management® (VLM®) technology which includes computational microstructural damage models to simulate the fatigue performance and calculate the lifetime of various product configurations. The framework probabilistically estimates the fatigue behavior of a range of Eaton gears and other products.

scholarly journals Bending Fatigue Behavior of 17-4 PH Gears Produced by Additive Manufacturing

2021 ◽  
Vol 11 (7) ◽  
pp. 3019
Author(s):  
Franco Concli ◽  
Luca Bonaiti ◽  
Riccardo Gerosa ◽  
Luca Cortese ◽  
Filippo Nalli ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Specific Resistance ◽  
Fatigue Behavior ◽  
Powder Bed ◽  
Bending Fatigue ◽  
Experimental Campaign ◽  
Single Tooth ◽  
Final Failure ◽  
Effective Design ◽  
Resistance Data

The introduction of Additive Manufacturing (AM) is changing the way in which components and machines can be designed and manufactured. Within this context, designers are taking advantage of the possibilities of producing parts via the addition of material, defining strategies, and exploring alternative design or optimization solutions (i.e., nonviable using subtractive technologies) of critical parts (e.g., gears and shafts). However, a safe and effective design requires specific resistance data that, due to the intrinsic modernity of additive technologies, are not always present in the literature. This paper presents the results of an experimental campaign performed on gear-samples made by 17-4 PH and produced via Laser Powder Bed Fusion (PBF-LB/M). The tests were executed using the Single Tooth Bending Fatigue (STBF) approach on a mechanical pulsator. The fatigue limit was determined using two different statistical approaches according to Dixon and Little. The obtained data were compared to those reported in the ISO standard for steels of similar performance. Additional analyses, i.e., Scanning Electron Microscopy SEM, were carried out to provide a further insight of the behavior 17-4PH AM material and in order to investigate the presence of possible defects in the tested gears, responsible for the final failure.

Gear root bending strength: a comparison between Single Tooth Bending Fatigue Tests and meshing gears

2021 ◽  
pp. 1-17
Author(s):  
Luca Bonaiti ◽  
Ahmed Bayoumi Mahmoud Bayoumi ◽  
Franco Concli ◽  
Francesco Rosa ◽  
Carlo Gorla
Keyword(s):  
Failure Modes ◽  
Bending Strength ◽  
Gear Tooth ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Gear Design ◽  
Single Tooth ◽  
Actual Strength ◽  
Meshing Gears ◽  
Definition Of

Abstract Gear tooth breakage due to bending fatigue is one of the most dangerous failure modes of gears. Therefore, the precise definition of tooth bending strength is of utmost importance in gear design. Single Tooth Bending Fatigue (STBF) tests are usually used to study this failure mode, since they allow to test gears, realized and finished with the actual industrial processes. Nevertheless, STBF tests do not reproduce exactly the loading conditions of meshing gears. The load is applied in a pre-determined position, while in meshing gears it moves along the active flank; all the teeth can be tested and have the same importance, while the actual strength of a meshing gear, practically, is strongly influenced by the strength of the weakest tooth of the gear. These differences have to be (and obviously are) taken into account when using the results of STBF tests to design gear sets. The aim of this paper is to investigate in detail the first aspect, i.e. the role of the differences between two tooth root stress histories. In particular, this paper presents a methodology based on high-cycle multi-axial fatigue criteria in order to translate STBF test data to the real working condition; residual stresses are also taken into account

Estimating the Endurance Limit of 9310, 4340M, and 4360 Steel Gears

2000 ◽  
Author(s):  
Chien Wern ◽  
Hormoz Zareh ◽  
Matt Carter ◽  
Kelly Jones ◽  
Mike Renzelmann
Keyword(s):  
Endurance Limit ◽  
Fatigue Behavior ◽  
Test Fixture ◽  
Bending Fatigue ◽  
Yield Load ◽  
Face Width ◽  
Single Tooth ◽  
Bending Fatigue Test ◽  
Number Of Cycles ◽  
Cycles To Failure

Abstract Single tooth bending fatigue behavior of three gear alloys, namely carburized 9310, induction hardened 4340M and 4360 alloys were examined. The alloys were fabricated into gears having a module of 2.12 (12 diametral pitch) with 12.7 mm (1/2 inch) face width. As the gear geometry was different from that recommended in SAE Single Tooth Gear Bending Fatigue Test standard (SAE-J1619), a test fixture was designed to accommodate these gears. The fixture has the added feature of conjugate action, not found in the SAE test standard. The gears were slowly bent in the fixture to determine the yield load. Then fatigue loads of 85%, 75%, and 65% of yield load were used to determine the number of cycles to failure. The expected endurance limit for single tooth bending fatigue was determined statistically from the finite portion of the load-cycles to failure curve.

scholarly journals Research on the Maximal Bearing Capacity Calculation of a New Double Ring Reducer Based on MATLAB

2015 ◽  
Vol 9 (1) ◽  
pp. 34-39
Author(s):  
Qiang Xu ◽  
Qi-sheng Xu ◽  
Dao-Yi Xu
Keyword(s):  
Bearing Capacity ◽  
Elastic Deformation ◽  
Gear Tooth ◽  
Bending Fatigue ◽  
Gear Teeth ◽  
Double Ring ◽  
Contact Points ◽  
Single Tooth ◽  
Capacity Calculation ◽  
Mathematical Relationships

The bearing capacity of a new double ring reducer increases with the increase of load because of the elastic deformation of the gear tooth. In order to solve the problem of its bearing capacity quantificationally, the concept of the maximal bearing capacity is put forward. Starting with that the single tooth bending stress is up to the bending fatigue strength, a mathematical model to determine the normal backlash of the gear teeth has been established, the maximal deformation of the single tooth has been determined. The mathematical relationships have also been setup between the normal backlashes of the tooth pairs, the maximal deformation and number of contact points, a corresponding MATLAB program is designed. The maximal bearing capacity of the reducer has been estimated through examples and proved by experiment. The results show that the calculation method is more effective and fully considers the factors that the elastic deformation of the gear tooth can increases its bearing capacity, so the structure of the reducer is more compact, which establishes the theory foundation for designing the reducer.

High Cycle Fatigue Behavior of Thermally Oxidized Ti6Al4V Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 2179-2182 ◽  
Author(s):  
Mehmet Cingi ◽  
Onur Meydanoglu ◽  
Hasan Guleryuz ◽  
Murat Baydogan ◽  
Huseyin Cimenoglu ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Yield Strength ◽  
Thermal Oxidation ◽  
Fatigue Behavior ◽  
Surface Hardness ◽  
Ti6al4v Alloy ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Bending Fatigue Strength

In this study, the effect of thermal oxidation on the high cycle rotating bending fatigue behavior of Ti6Al4V alloy was investigated. Oxidation, which was performed at 600°C for 60 h in air, considerably improved the surface hardness and particularly the yield strength of the alloy without scarifying the tensile ductility. Unfortunately, the rotating bending fatigue strength at 5x106 cycles decreased from about 610 MPa to about 400 MPa upon oxidation. Thus, thermal oxidation leaded a reduction in the fatigue strength of around 34%, while improving the surface hardness (HV0.1) and yield strength 85 % and 36 %, respectively.

Improvement of Fatigue Behaviour of High Strength Aluminium Alloys by Fluidized Bed Peening (FBP)

2007 ◽  
Vol 344 ◽  
pp. 87-96 ◽  
Author(s):  
M. Barletta ◽  
F. Lambiase ◽  
Vincenzo Tagliaferri
Keyword(s):  
Fatigue Life ◽  
Fluidized Bed ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Maximum Amplitude ◽  
High Strength ◽  
Operational Parameters ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

This paper deals with a definition of a relatively novel technique to improve the fatigue behavior of high strength aluminum alloys, namely, Fluidized Bed Peening (FBP). Fatigue samples made from AA 6082 T6 alloy were chosen according to ASTM regulation about rotating bending fatigue test and, subsequently, treated by varying FBP operational parameters and fatigue testing conditions. First, a full factorial experimental plan was performed to assess the trend of number of cycles to rupture of fatigue samples varying among several experimental levels the factors peening time and maximum amplitude of alternating stress applied to fatigue samples during rotating bending fatigue tests. Second, design of experiment (DOE) technique was used to analyze the influence of FBP operational parameters on fatigue life of AA 6082 T6 alloy. Finally, ruptures of FB treated samples and untreated samples were discussed in order to evaluate the influence of operational parameters on the effectiveness of FBP process and to understand the leading process mechanisms. At any rate, the fatigue behavior of processed components was found to be significantly improved, thereby proving the suitability of FBP process as alternative mechanical technique to enhance fatigue life of components made from high strength aluminum alloy.

Displacement-controlled flexural bending fatigue behavior of graphene/epoxy nanocomposites

2013 ◽  
Vol 48 (24) ◽  
pp. 2935-2944 ◽  
Author(s):  
MM Shokrieh ◽  
M Esmkhani ◽  
F Taheri-Behrooz ◽  
AR Haghighatkhah
Keyword(s):  
Fatigue Behavior ◽  
Epoxy Nanocomposites ◽  
Bending Fatigue

scholarly journals Pitting and Bending Fatigue Evaluations of a New Case-Carburized Gear Steel

2007 ◽  
Author(s):  
Timothy Krantz ◽  
Brian Tufts
Keyword(s):  
Power Density ◽  
Fatigue Testing ◽  
Surface Hardness ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Surface Fatigue ◽  
Gear Steel ◽  
Single Tooth ◽  
Carburized Gear ◽  
Gear Steels

The power density of a gearbox is an important consideration for many applications and is especially important for gearboxes used on aircraft. One approach to improving power density of gearing is to improve the steel properties by design of the alloy. The alloy tested in this work was designed to be case-carburized with surface hardness of Rockwell C66 after hardening. Test gear performance was evaluated using surface fatigue tests and single-tooth bending fatigue tests. The performance of gears made from the new alloy was compared to the performance of gears made from two alloys currently used for aviation gearing. The new alloy exhibited significantly better performance in surface fatigue testing, demonstrating the value of the improved properties in the case layer. However, the alloy exhibited lesser performance in single-tooth bending fatigue testing. The fracture toughness of the tested gears was insufficient for use in aircraft applications as judged by the behavior exhibited during the single tooth bending tests. This study quantified the performance of the new alloy and has provided guidance for the design and development of next generation gear steels.

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