Prediction of fatigue strength of micro-specimen on copper and aluminium alloys under rotating bending load

2020 ◽  
Author(s):  
Haftirman ◽  
Teguh Prioyono ◽  
Muhammad Kholil ◽  
Dinalant Al Tanggaraju ◽  
Mohd Arif Anuar Mohd Salleh ◽  
...  
Author(s):  
D. Fuchs ◽  
S. Schurer ◽  
T. Tobie ◽  
K. Stahl

AbstractDemands on modern gearboxes are constantly increasing, for example to comply with lightweight design goals or new CO2 thresholds. Normally, to increase performance requires making gearboxes and powertrains more robust. However, this increases the weight of a standard gearbox. The two trends therefore seem contradictory. To satisfy both of these goals, gears in gearboxes can be shot-peened to introduce high compressive residual stresses and improve their bending fatigue strength. To determine a gear’s tooth root bending fatigue strength, experiments are conducted up to a defined number of load cycles in the high cycle fatigue range. However, investigations of shot-peened gears have revealed tooth root fracture damage initiated at non-metallic inclusions in and above the very high cycle fatigue range. This means that a further reduction in bending load carrying capacity has to be expected at higher load cycles, something which is not covered under current standard testing conditions. The question is whether there is a significant decrease in the bending load carrying capacity and, also, if pulsating tests conducted at higher load cycles—or even tests on the FZG back-to-back test rig—are necessary to determine a proper endurance fatigue limit for shot-peened gears. This paper examines these questions.


2007 ◽  
Vol 561-565 ◽  
pp. 2179-2182 ◽  
Author(s):  
Mehmet Cingi ◽  
Onur Meydanoglu ◽  
Hasan Guleryuz ◽  
Murat Baydogan ◽  
Huseyin Cimenoglu ◽  
...  

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.


2012 ◽  
Vol 457-458 ◽  
pp. 1025-1031 ◽  
Author(s):  
Koshiro Mizobe ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
...  

Martensitic high carbon high strength SAE 52100 bearing steel is one of the main alloys used for rolling contact applications where high wear resistance are required. Due to its high fatigue strength, SAE 52100 is recently being used not only for the production of bearings but also shafts. Refining of prior austenite grain through repeated quenching is a procedure that can be used to enhance the material’s strength. In this work, the microstructure of repeatedly quenched SAE 52100 steel and its fatigue strength under rotating bending were investigated. It was found that repeated furnace heating and quenching effectively refined the martensitic structure and increased the retained austenite content. Repeated quenching was found to improve the fatigue strength of SAE 52100.


Trudy NAMI ◽  
2021 ◽  
pp. 25-33
Author(s):  
V. G. Chelnokov ◽  
B. V. Savel'ev

Introduction (problem statement and relevance). Wheels are components that ensure the safety of vehicles. One of the main ways to test the fatigue strength of wheels is a rotating bending load test. The methodology of these tests, regulated by international and national regulatory documents, allows an indirect method for measuring the normalized force effect on the wheels, in which there are always risks of methodological errors.The purpose of the study was to identify potential sources of methodological errors when testing wheels in the bending-rotating mode.Methodology and research methods. Analytical research methods from the field of practical vibration theory were used in the article, considering the critical state of rotating shafts and rotors. Scientific novelty and results. The sources of potential methodological errors and their relationship with the design characteristics of the bench equipment and the wheel itself were determined.Practical significance. Practical recommendations have been given on the change and control of the stand components design characteristics aimed at minimizing errors. The high-speed test modes were determined, in which the error of the test effect on the wheel did not go beyond the normative limits.


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