Effect of machine scatter on the rotating bending fatigue life of materials

2018 ◽  
Vol 27 (3-4) ◽  
Author(s):  
Shashidhar M. Banavasi ◽  
K.S. Ravishankar ◽  
Padmayya S. Naik
Keyword(s):  
Fatigue Life ◽  
Fatigue Cracks ◽  
Test Results ◽  
Angular Misalignment ◽  
Bending Fatigue ◽  
Transverse Vibrations ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Set Up

AbstractRotating bending fatigue test results vary from specimen to specimen even if materials are tested in a standard laboratory set up because rotating bending fatigue life or fatigue strength depends upon various factors due to its dynamic action. One method of testing may be machine scatter (offset and angular misalignment). Angular misalignments are unavoidable in dynamic machines due to continuous operation leading to transverse vibrations in specimens. The magnitude of transverse vibrations was measured manually by dial gauge arrangement. Experiments were carried out until fracture either with smooth running conditions or with the effects of offset and angular misalignment. The enhanced effect of misalignments on fatigue life was done through the histogram normal distribution technique. There was a clear distinction between the appearances of the fracture surfaces between the specimens subjected to smooth running conditions and specimen vibration, which reveals general fatigue fracture phenomena and intergranular fatigue cracks, larger decohesion of graphite nodules and isolated cleavage facets. The manual technique used without any resistance strain gauges, as they were not efficiently sustainable under repetitive loads, helped in understanding the dynamic machine scatter on fatigue life in an economical way where there were lesser concentrations in these areas.

Experiment Research on the Influence of Fretting on Crack Propagation

2011 ◽  
Vol 228-229 ◽  
pp. 617-620 ◽  
Author(s):  
Guang Xue Yang ◽  
Qiang Li ◽  
Ji Long Xie
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Fretting Fatigue ◽  
Experimental Result ◽  
Test Machine ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Shrink Fit

In order to investigate the influence of fretting induced by a shrink-fit shaft and hub subjected to rotating bending on crack propagation on different position, small specimens consisted of shaft and hub were tested on the four point rotating bending fatigue test machine. The experimental result shows that the fretting fatigue life of specimen with notch outside the shaft-hub contact is shortest, and the fretting fatigue life of specimen with notch inside the shaft-hub contact is longest.

A FAST ROTATING BENDING FATIGUE TEST MACHINE

2017 ◽  
Author(s):  
Marco Antonio Meggiolaro ◽  
Jaime T P Castro ◽  
Rodrigo de Moura Nogueira
Keyword(s):  
Fatigue Test ◽  
Test Machine ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Fast Rotating

A Study onP-S-NCurve for Rotating Bending Fatigue Test for Bearing Steel

2008 ◽  
Vol 51 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Katsuji Tosha ◽  
Daisuke Ueda ◽  
Hirokazu Shimoda ◽  
Shigeo Shimizu
Keyword(s):  
Fatigue Test ◽  
Bearing Steel ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

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.

Improvement of Fatigue Strength of Aluminum Alloy by Cavitation Shotless Peening

2002 ◽  
Vol 124 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Hitoshi Soyama ◽  
Kenichi Saito ◽  
Masumi Saka
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Shot Peening ◽  
High Speed ◽  
Bending Fatigue ◽  
Hydraulic Machinery ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Cavitation Shotless Peening

Cavitation impact, which normally produces severe damage in hydraulic machinery, can be used to modify surfaces in the same way as shot peening. Cavitation impact enables the surface of a material to be peened without the use of shot, thus it is called cavitation shotless peening. As there are no solid body collisions occurring in this peening process, the roughness of the peened surface should be less than that produced by shot peening. This characteristic makes it suitable for peening soft metals. In order to demonstrate the improvement of the fatigue strength of aluminum alloy by this process, specimens were subjected to the process, and then tested in a rotating bending fatigue test. Cavitation impacts were produced and controlled by using a submerged high speed water jet with cavitation, i.e., a cavitating jet. It was revealed that the fatigue strength of an aluminum alloy specimen treated by this peening process was 50% stronger than that of a specimen without peening.

Heat treatment effect on fatigue behavior of 3D-printed maraging steels

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tugce Tezel ◽  
Volkan Kovan
Keyword(s):  
Heat Treatment ◽  
Fatigue Test ◽  
Fatigue Behavior ◽  
Content Type ◽  
Bending Fatigue ◽  
Maraging Steels ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Service Conditions

Purpose This study aims to reveal that fatigue life is improved using heat treatment in the rotational bending fatigue test, which determines the fatigue behavior closest to service conditions. Design/methodology/approach It is essential to know the mechanical behavior of the parts produced by additive manufacturing under service conditions. In general, axial stress and plane bending tests are used by many researchers because they are practical: the service conditions cannot be sufficiently stimulated. For this reason, the rotating bending fatigue test, which represents the conditions closest to the service conditions of a load-bearing machine element, was chosen for the study. In this study, the rotational bending fatigue behavior of X3NiCoMoTi18-9–5 (MS1) maraging steel specimens produced by the selective laser melting (SLM) technique was experimentally investigated under various heat treatments conditions. Findings As a result of the study, MS1 produced by additive manufacturing is a material suitable for heat treatment that has enabled the heat treatment to affect fatigue strength positively. Cracks generally initiate from the outer surface of the sample. Fabrication defects have been determined to cause all cracks on the sample surface or regions close to the surface. Research limitations/implications While producing the test sample, printing was vertical to the print bed, and various heat treatments were applied. The rotating bending fatigue test was performed on four sample groups comprising as-fabricated, age-treated, solution-treated and solution + age-treated conditions. Originality/value Most literature studies have focused on the axial fatigue strength, printing orientation and heat treatment of maraging steels produced with Direct Metal Laser Sintering (DMLS); many studies have also investigated crack propagation behaviors. There are few studies in the literature covering conditions of rotating bending fatigue. However, the rotating bending loading state is the service condition closest to modern machine element operating conditions. To fill this gap in the literature, the rotating bending fatigue behavior of the alloy, which was maraging steel (X3NiCoMoTi18-9–5, 1.2709) produced by SLM, was investigated under a variety of heat treatment conditions in this study.

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