Novel Bending Fatigue Testing of Small Medical Device Cables

Metal free reeds are used for musical instruments like harmonica. Free reeds are small, thin cantilevers, and oscillate by blowing air. It is reported that free reeds break due to fatigue during play. In order to elongate the life of free reeds, the fatigue properties should be investigated and a motion analysis method should be developed. The experimental and analytical research on metal free reed, however, has been rarely reported. In this study, two types of fatigue testing machines were developed to obtain basic fatigue characteristics. The fatigue testing machines are designed for bending fatigue of actual free reeds whose thickness is less than 400 μm. An S-N diagram is successfully obtained up to 107 cycles by using the developed fatigue testing machines. The fracture surfaces of fatigued specimens are in good agreement with those of free reeds failed in use. Then, an analytical method for the self-excited oscillation of free reeds was developed based on a mass-damper-spring model. The proposed method can take account for the shape of free reed. The self-excited oscillation of free reeds with different shape are analyzed and in good agreement with experimental results.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.344.87 ◽

2007 ◽

Vol 344 ◽

pp. 87-96 ◽

Cited By ~ 2

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.

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Test Method for Bending Fatigue Testing for Copper-Alloy Spring Materials

10.1520/b0593-21 ◽

2021 ◽

Author(s):

Keyword(s):

Copper Alloy ◽

Fatigue Testing ◽

Test Method ◽

Bending Fatigue

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A Novel Prediction Perspective to the Bending Over Sheave Fatigue Lifetime of Steel Wire Ropes by Means of Artificial Neural Networks

Artificial Intelligence and Machine Learning Applications in Civil, Mechanical, and Industrial Engineering - Advances in Computational Intelligence and Robotics ◽

10.4018/978-1-7998-0301-0.ch003 ◽

2020 ◽

pp. 39-58

Author(s):

Tuğba Özge Onur ◽

Yusuf Aytaç Onur

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

Fatigue Testing ◽

Steel Wire ◽

Experimental Studies ◽

Fatigue Lifetime ◽

Bending Fatigue ◽

Wire Ropes ◽

Significant Case ◽

Artificial Neural

Steel wire ropes are frequently subjected to dynamic reciprocal bending movement over sheaves or drums in cranes, elevators, mine hoists, and aerial ropeways. This kind of movement initiates fatigue damage on the ropes. It is a quite significant case to know bending cycles to failure of rope in service which is also known as bending over sheave fatigue lifetime. It helps to take precaution in the plant in advance and eliminate catastrophic accidents due to usage of rope when allowable bending cycles are exceeded. To determine bending fatigue lifetime of ropes, experimental studies are conducted. However, bending over sheave fatigue testing in laboratory environments require high initial preparation cost and longer time to finalize the experiments. Due to those reasons, this chapter focuses on a novel prediction perspective to the bending over sheave fatigue lifetime of steel wire ropes by means of artificial neural networks.

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Continuous Estimation of the Crack Growth Rate during Rotating‒Bending Fatigue Testing

Metals ◽

10.3390/met9030275 ◽

2019 ◽

Vol 9 (3) ◽

pp. 275 ◽

Cited By ~ 1

Author(s):

Gabriela Martinez-Cazares ◽

Rafael Mercado-Solis ◽

Yaneth Bedolla-Gil ◽

Diego Lozano

Keyword(s):

Growth Rate ◽

Crack Growth Rate ◽

Crack Growth ◽

Fatigue Testing ◽

Crack Nucleation ◽

Bending Fatigue ◽

Initial Load ◽

Rotating Bending Fatigue ◽

Rotating Bending ◽

Continuous Estimation

A method for estimating the crack growth rate in steel during rotating‒bending fatigue testing is presented. Constant deflection tests were conducted in which the initial load remained constant prior to crack nucleation, when it decreased as the crack grew. In the proposed approach, steel samples were sharp-notched to produce a characteristic circular fracture upon loading and the final fracture area was correlated with a ratio of the load prior to fracture and the initial load. In this method, the deflection imposed is a function of a material’s elastic modulus rather than its yield strength and the correlation obtained to estimate the average crack length as a function of the instantaneous load is independent of the applied stress or steel grade.

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

Volume 7: 10th International Power Transmission and Gearing Conference ◽

10.1115/detc2007-34090 ◽

2007 ◽

Cited By ~ 5

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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