The use of the high-frequency fatigue test as a method for accelerated estimation of endurance characteristics of materials

This paper proposes an ultra-high frequency (UHF) fatigue test of a titanium alloy TA11 based on electrodynamic shaker in order to develop a feasible testing method in the VHCF regime. Firstly, a type of UHF fatigue specimen is designed to make its actual testing frequency reach as high as 1756 Hz. Then the influences of the loading frequency and loading types on the testing results are considered separately, and a series of comparative fatigue tests are hence conducted. The results show the testing data from the present UHF fatigue specimen agree well with those from the conventional vibration fatigue specimen with the loading frequency of 240 Hz. Furthermore, the present UHF testing data show good consistency with those from the axial-loading fatigue and rotating bending fatigue tests. But the obtained fatigue life from ultrasonic fatigue test with the loading frequency of 20 kHz is significantly higher than all other fatigue test results. Thus the proposed ultra-high frequency vibration-based fatigue test shows a balance of high efficiency and similarity with the conventional testing results.

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Structural Improvement of the ω-Type High-Speed Rail Clip Based on a Study of Its Failure Mechanism

Shock and Vibration ◽

10.1155/2019/4127065 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Xiaogang Gao ◽

Anbin Wang ◽

Yu He ◽

Xiaohan Gu

Keyword(s):

Failure Mechanism ◽

Fatigue Test ◽

High Frequency ◽

High Speed ◽

Excitation Frequency ◽

Test System ◽

Vibration Measurement ◽

High Speed Rail ◽

Resonant Frequencies ◽

Rail Wear

In the circumstances of high-speed railways, the wheel-rail vibration is significantly aggravated by polygonal wheel wear and rail corrugation, which subsequently leads to the wheel-rail interaction at higher frequencies and potential failure of the rail fastening. In this paper, a ω-type clip of the fastening in the CRH high-speed rail was used to investigate the failure mechanism. First, a dynamic wheel-rail coupling model and a finite element analysis of the rail clip were developed, from which the rail vibration frequency and modal frequencies of the clip with different installation torques were obtained. The experimental tests and modal simulation results were mutually verified. In addition, the real-time vibration measurement and the wheel-rail wear monitoring were carried out at a CRH high-speed railway site. It was found that the resonant frequencies of the ω-type clip in the installation condition coincided with the excitation frequencies of the wheel-rail interaction induced by wheel-rail wear. The high-frequency dynamic failure mechanism of a typical ω-type clip, W300-1, is put forward for the first time. Moreover, a high-frequency rail clip fatigue test system was designed and developed specifically for this study. The loading excitation frequency of the clip test used was set as 590 Hz, and the loading amplitude was 0.05 mm. After 125-minute operation of the test system, the clip was broken at the expected location predicted by the FEA model. The high-frequency fatigue test result further verified that the failure mechanism of the ω-type clip was due to the resonance of the clip with its excitation force from the wheel-rail interaction. Finally, the clip was then structurally improved taking into account the stiffness and mass, which led to its resonant frequencies shifting away from the high-frequency excitation range, hence avoiding resonance failure of the subject clip.

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PVDF actuator for high-frequency fatigue test of thin-film metals

IEEJ Transactions on Electrical and Electronic Engineering ◽

10.1002/tee.21840 ◽

2013 ◽

Vol 8 (2) ◽

pp. 199-205 ◽

Cited By ~ 5

Author(s):

Nastaran Tamjidi ◽

Kohei Sato ◽

Junpei Sakurai ◽

Seiichi Hata

Keyword(s):

Thin Film ◽

Fatigue Test ◽

High Frequency

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Development of a fatigue test machine for high frequency applications

Procedia Engineering ◽

10.1016/j.proeng.2011.04.480 ◽

2011 ◽

Vol 10 ◽

pp. 2892-2897 ◽

Cited By ~ 11

Author(s):

C. Ghielmetti ◽

R. Ghelichi ◽

M. Guagliano ◽

F. Ripamonti ◽

S. Vezzù

Keyword(s):

Fatigue Test ◽

High Frequency ◽

Test Machine

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Energy dissipation in metals in high-frequency fatigue test. II

Strength of Materials ◽

10.1007/bf01527839 ◽

1972 ◽

Vol 4 (7) ◽

pp. 856-859 ◽

Cited By ~ 3

Author(s):

V. A. Kuz'menko ◽

A. I. Afonin

Keyword(s):

Energy Dissipation ◽

Fatigue Test ◽

High Frequency

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Fatigue Performance of the CA Mortar Used in CRTS I Ballastless Slab Track under Simulated Servicing Condition

Materials ◽

10.3390/ma11112259 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2259 ◽

Cited By ~ 6

Author(s):

Yuchuan Shan ◽

Shuguang Zheng ◽

Xuefeng Zhang ◽

Wei Luo ◽

Jingda Mao ◽

...

Keyword(s):

Fatigue Test ◽

High Frequency ◽

High Speed ◽

Comfort Level ◽

Polymer Emulsion ◽

High Speed Railway ◽

High Frequency Vibration ◽

Vibration Load ◽

Slab Track ◽

Ca Mortar

The cement and asphalt mortar (CA mortar) used in the China Railway Track System (CRTS) I ballastless slab track may encounter a coupling fatigue effect under the high-frequency vibration, load and high-and-low temperature cycles, and the deterioration under fatigue may happen during service of the high-speed railway. In this study, the performance degradation and its mechanism of the CA mortar with and without polymer emulsion incorporated under the coupling fatigue effects of the high-frequency vibration, load and temperature were studied by using an anti-fatigue testing device specially developed for the CA mortar used in the ballastless slab track of the high-speed railway. The results showed that the deformation capacity of the CA mortar for CRTS I slab ballastless slab track decreased after fatigue test under simulated service environment, presenting a typical brittle characteristic and an obvious reduction of the ductility and toughness. The Scanning Electron Microscopy (SEM) observation and the mercury intrusion porosimetry (MIP) analysis showed that the volume of the macropore decreased whereas that of the micropore increased after the fatigue test. The asphalt in the hardened CA mortar revealed a softening and migration from the bulk paste to fill the pore and make the structure denser and even ooze out of the CA mortar under the high-frequency vibration and high temperature. Through incorporating the polymer emulsion, the anti-fatigue property of the CA mortar was obviously improved, which can prevent the CA mortar from losing its elastic adjustment function too early. Though increase of the strength and elastic modulus for the CA mortar after severe service is beneficial to the stability of train running, the comfort level and safety of the train operation may decline due to the gradual reduction of the ductility & toughness and the gradual loss of the elastic damping adjustment function of the CA mortar between the base concrete slab and the track slab.

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

ASME 2010 Pressure Vessels and Piping Conference: Volume 5 ◽

10.1115/pvp2010-25531 ◽

2010 ◽

Cited By ~ 1

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.

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