Experimental Study on Critical Derivative of Cracking Magnetic Field Intensity in High Frequency Fatigue Test

2010 ◽  
Author(s):  
Yi-liang Zhang ◽  
Rui-bin Gou ◽  
Ji-min Li ◽  
Gong-tian Shen ◽  
Jing Wang
Keyword(s):  
Fatigue Test ◽  
High Frequency ◽  
High Cycle Fatigue ◽  
Magnetic Field Intensity ◽  
Fatigue Crack Initiation ◽  
Engineering Application ◽  
Magnetic Memory ◽  
Metal Magnetic Memory ◽  
Cycle Fatigue ◽  
Metal Structures

This paper focuses on engineering application of metal magnetic memory (MMM) method. High-cycle fatigue test were applied to a large number of defect-free samples, and MMM signals were captured before fatigue fracturing. A concept of critical magnetic intensity (Hp) derivative (dHp/dx) of cracking was proposed. To study the characteristics of Hp and its derivative (dHp/dx) during cracking, fatigue test were applied to a total number of 50 pieces of Q235, 16MnR and base metal and welded specimens. In different fatigue periods, MMM signals were tested and microscopic metallographic were observed, so as to quantitatively analyze Hp and dHp/dx from both macro and micro angles. The results show that various materials differ in their critical dHp/dx limit, which could be the fatigue crack initiation time. It thus proves that MMM has special efficiency in the diagnosis of premature defects and stress concentration of metal structures.

A Rapid Fatigue Test Method on Micro Structures for High-Cycle Fatigue

2016 ◽  
Vol 16 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Yi-Chueh Shieh ◽  
Hsuan-Yu Lin ◽  
Wensyang Hsu ◽  
Yu-Hsin Lin
Keyword(s):  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Test Method ◽  
Cycle Fatigue ◽  
Micro Structures

Tensile and high cycle fatigue test of Al–3% Ti thin films

2008 ◽  
Vol 147 (2) ◽  
pp. 561-569 ◽  
Author(s):  
Jun-Hyub Park ◽  
Man Sik Myung ◽  
Yun-Jae Kim
Keyword(s):  
Thin Films ◽  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Cycle Fatigue

The Effect of HFPD Thermally Sprayed WC-Co Coatings on the Fatigue Behavior and Deformation of Al 2024-T4

2000 ◽  
Author(s):  
A. Ibrahim ◽  
C.C. Berndt
Keyword(s):  
High Frequency ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Pulse Detonation ◽  
Deformation Behaviors ◽  
Life Distributions ◽  
Thermally Sprayed ◽  
Al 2024 ◽  
Frequency Pulse

Abstract The effect of high frequency pulse detonation (HFPD) and HVOF thermally sprayed WC-Co coatings on the high cycle fatigue (HCF) behavior of 2024-T4 aluminum was investigated. The fatigue life distributions of specimens in the polished and coated conditions are presented as a function of the probability of failure. The monotonic and cyclic deformation behaviors of the as-received and as-coated specimens were investigated. The conclusions show that, (i) the HFPD sprayed specimens exhibited slightly higher fatigue lives compared to the uncoated specimens, (ii) the HVOF sprayed specimens exhibited significantly higher fatigue lives compared to the uncoated specimens, and (iii) the as-coated specimen was cyclically stable.

Effect of Plasma Nitriding on Ultra-High Cycle Fatigue Behaviors of Ti-6Al-4V

2011 ◽  
Vol 295-297 ◽  
pp. 2386-2389 ◽  
Author(s):  
Ren Hui Tian ◽  
Qiao Lin Ouyang ◽  
Qing Yuan Wang
Keyword(s):  
High Cycle Fatigue ◽  
Plasma Nitriding ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue ◽  
Stress Ratios

In order to investigate the effect of plasma nitriding treatment on fatigue behavior of titanium alloys, very high cycle fatigue tests were carried out for Ti-6Al-4V alloy using an ultrasonic fatigue machine under load control conditions for stress ratios of R=-1 at frequency of ƒ=20KHz. Experiment results showed that plasma nitriding treatment played the principal role in the internal fatigue crack initiation. More importantly, plasma nitriding treatment had a detrimental effect on fatigue properties of the investigated Ti-6Al-4V alloy, and the fatigue strength of material after plasma nitriding treatment appeared to be significantly reduced about 17% over the untreated material.

Very High Cycle Fatigue Testing under Spectrum Loading for Endurance Limit Structural Design

2020 ◽  
Vol 65 (1) ◽  
pp. 1-7
Author(s):  
David T. Rusk ◽  
Robert E. Taylor ◽  
Bruce A. Pregger ◽  
Luis J. Sanchez
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Crack Nucleation ◽  
Peak Stress ◽  
Material Behavior ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High

A program has recently concluded that generated fatigue test data for the influence of a rotorcraft main rotor blade root bending spectrum (Helix) on the crack nucleation mechanisms in 7075-T651 aluminum. High-frequency tests were performed that generated spectrum fatigue failures out to nearly 109 cycles. Fractographic examination showed a distinct change in crack nucleation from slip initiated to inclusion-initiated cracking as the spectrum peak stress level was increased. Spectrum life predictions were made using three different baseline constant-amplitude S-N curves, one using a traditional rotorcraft original equipment manufacturer fitting methodology, one using the high-cycle fatigue (HCF) portion of a strainlife curve, and one that was fitted to S-N data with test lives out to 3×108 cycles. The spectrum life prediction using the S-N curve that properly modeled material behavior in the very high cycle fatigue regime provided a good correlation to the spectrum fatigue test data. Predictions using the other S-N curves were highly conservative.

Influence of Ni5Zr Particles on Fatigue Property of Ni3Al Alloy

1994 ◽  
Vol 364 ◽  
Author(s):  
Gang Li ◽  
Jian-Ting Guo ◽  
Zhong-Guang Wang
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Property ◽  
Fatigue Tests ◽  
Al Alloy ◽  
Second Phase ◽  
Cycle Fatigue ◽  
Second Phase Particles ◽  
Minimum Stress

AbstractIn this investigation, the influence of second phase particles on high cycle fatigue behavior of Ni3Al alloy is studied. A single phase Ni3Al-B alloy and a Ni3Al-B/Zr alloy with a few second phase particles (Ni5Zr) at the grain boundaries are selected for investigation. High cycle fatigue tests at room temperature with R (minimum stress/maximum stress) 0.1 are conducted in air and at 30 Hz. The results show that the second phase particles are detrimental to high cycle fatigue resistance. It may be explained in terms of the second phase particles promoting fatigue crack initiation. The characteristics of fracture surfaces are examined by Scanning Electron Microscopy (SEM).

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