scholarly journals Flexural Fatigue Behaviors of Silicon Carbide Recycled Concrete in Corrosive Environments

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jinzhi Zhou ◽  
Tiantian Fu ◽  
Chuheng Zhong ◽  
Kun Peng ◽  
Ziyang Shuang
Keyword(s):  
Silicon Carbide ◽  
Fatigue Life ◽  
Failure Probability ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Recycled Concrete ◽  
Flexural Fatigue ◽  
Corrosive Environments ◽  
The Relationship

An experimental study on the flexural fatigue behaviors of recycled concrete (RC) and silicon carbide recycled concrete (SiCRC) was conducted. The immersion time was 0 d, 30 d, 60 d, and 90 d in 5% NaCl solution for these two kinds of recycled concrete specimens, respectively, and then, four-point flexural fatigue tests were performed by MTS fatigue testing machine. The fatigue life for varying stress levels ranging from 0.9 to 0.6 was obtained. The fatigue life was given considering the failure probability according to the fatigue life and stress level of the specimen via the logarithmic normal distribution and Weibull distribution, respectively. The relationship between fatigue life and failure probability was also obtained. The fatigue life with failure probability of 1% and 50% was further predicted. The results showed that the fatigue life of RC and SiCRC increased in corrosive environments. The fatigue life of SiCRC is higher than that of RC, and the incorporation of SiCRC can improve the fatigue life of recycled concrete.

A Study on Fatigue Behavior of SM490A Steel under Low Temperature

2007 ◽  
Vol 353-358 ◽  
pp. 142-145 ◽  
Author(s):  
Ki Weon Kang ◽  
Byeong Choon Goo ◽  
J.H. Kim ◽  
Heung Seob Kim ◽  
Jung Kyu Kim
Keyword(s):  
Fatigue Life ◽  
Low Temperature ◽  
Test Temperature ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Static Strength ◽  
Experimental Results ◽  
Railway Vehicle

This paper deals with the fatigue behavior and its statistical properties of SM490A steel at various temperatures, which is utilized in the railway vehicle. For these goals, the tensile ad fatigue tests were performed by using a servo-hydraulic fatigue testing machine at three temperatures: +20°C, -10°C and -40°C. The static strength and fatigue limits of SM490A steel were increased with decreasing of test temperature. The probabilistic properties of fatigue behavior are investigated by means of probabilistic stress-life (P-S-N) curve and they are well in conformance with the experimental results regardless of temperature. Also, based on P-S-N curves, the variation of fatigue life is investigated and as the temperature decreases, the variation of fatigue life increases moderately.

scholarly journals Bending and Torsion Fatigue-Testing Machine Developed for Multiaxial Non-Proportional Loading

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1115 ◽  
Author(s):  
Fumio Ogawa ◽  
Yusuke Shimizu ◽  
Stefano Bressan ◽  
Takahiro Morishita ◽  
Takamoto Itoh
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
304 Stainless Steel ◽  
Testing Time ◽  
Loading Conditions ◽  
Proportional Loading ◽  
Bending Loading

A new fatigue-testing machine was developed to perform high-cycle multiaxial fatigue tests at 50 Hz, in order to reduce testing time. The developed machine can combine bending and torsion loading and perform fatigue tests at a high frequency, under proportional and non-proportional loading conditions, where the principal stress direction changes during a cycle. The proportional loading is cyclic bending loading, and the non-proportional loading is cyclic, combining bending and reversed torsion loading. In this study, the effectiveness of the testing machine was verified by conducting tests under these loading conditions, using specimens of type 490A hot-rolled steel and type 304 stainless steel. The fatigue life linked to bending loading obtained using the new testing machine was slightly extended compared with that obtained using the conventional fatigue-testing machine. The fatigue life derived as a result of a combination of bending and torsion was comparable to that obtained using the conventional fatigue-testing machine, although a fatigue limit reduction of 100 MPa was observed compared to the former study. The feasibility of tests using the developed multiaxial fatigue-testing machine was confirmed.

The effect of repetitive magnetic and cyclic loading on the fatigue life prediction of a magnetorheological elastomer

2021 ◽  
pp. 009524432110386
Author(s):  
Seyyed Mohammad Hosseini ◽  
Mohammad Hassan Shojaeefard ◽  
Hamed Saeidi Googarchin
Keyword(s):  
Magnetic Field ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Maximum Stress ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Magnetorheological Elastomer ◽  
Hyper Elastic ◽  
The Magnetic Field

Prediction of fatigue life is particularly crucial in magnetorheological elastomer (MRE) based rubber components, especially when are exposed to repetitive magnetic and cyclic loading. MREs are smart composites that contain soft elastomer matrix and carbonyl iron particles (CIPs). In this research, silicon rubber was mixed with 20% of CIPs in the absence of an external magnetic field to produce MREs. Firstly, for the determination of material constants (including hyper elastic, magnetic, and viscoelastic), two types of tests such as uniaxial compression and relaxation, were performed on the samples. Then, fatigue tests were performed by a servo-hydraulic fatigue testing machine with cyclic loading in a repetitive magnetic field. Fatigue equations were obtained based on the number of fatigue life and maximum stress. The results confirmed that maximum stress could be used as a trustworthy fatigue life predictor for MREs when they are subjected to a combination of repetitive magnetic and cyclic loading. Scanning electron microscopy images from fatigue crack showed that the internal structure of MREs became stronger in the direction of the magnetic field. The maximum stress of the MRE was smaller in the absence of a magnetic field and decreased as the number of fatigue cycles increased with and without the magnetic field.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Prototype of Compact Flexural Fatigue Testing Machine

2014 ◽  
Vol 554 ◽  
pp. 350-354
Author(s):  
Muhammad Azrie Husainy Mohd Jasri ◽  
Mohd Afendi ◽  
A.H.M. Fauzi
Keyword(s):  
Fatigue Failure ◽  
Electromagnetic Force ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Working Environment ◽  
Motion Sensor ◽  
Flexural Fatigue ◽  
The Real ◽  
The Cost ◽  
Dynamic Fatigue

The purpose of this project is to build a prototype of compact flexural fatigue testing machine and to strive for an easy working-environment as required by the users besides cutting the cost of the machining. This particular project is about to build the prototype of compact flexural fatigue testing machine in compact mode. In this project, the prototype will be functioning 60% similar to the real fatigue machine which is Dynamic Fatigue Testing Machine (INSTRON) due to timer counter, frequency and load applied. But the new invention is this prototype was using the concept of electromagnetic force relay that will apply to the specimen using the application of basic electronics. The motion sensor also being applied to this prototype to achieve accurate results when the specimen breaks up after undergoes a fatigue failure.

scholarly journals Experimental Design and Validation of an Accelerated Random Vibration Fatigue Testing Methodology

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Jiang ◽  
Gun Jin Yun ◽  
Li Zhao ◽  
Junyong Tao
Keyword(s):  
Fatigue Life ◽  
Stress Responses ◽  
Life Prediction ◽  
Random Vibration ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Fatigue Life Prediction ◽  
Power Spectral ◽  
Vibration Fatigue ◽  
Non Gaussian

Novel accelerated random vibration fatigue test methodology and strategy are proposed, which can generate a design of the experimental test plan significantly reducing the test time and the sample size. Based on theoretical analysis and fatigue damage model, several groups of random vibration fatigue tests were designed and conducted with the aim of investigating effects of both Gaussian and non-Gaussian random excitation on the vibration fatigue. First, stress responses at a weak point of a notched specimen structure were measured under different base random excitations. According to the measured stress responses, the structural fatigue lives corresponding to the different vibrational excitations were predicted by using the WAFO simulation technique. Second, a couple of destructive vibration fatigue tests were carried out to validate the accuracy of the WAFO fatigue life prediction method. After applying the proposed experimental and numerical simulation methods, various factors that affect the vibration fatigue life of structures were systematically studied, including root mean squares of acceleration, power spectral density, power spectral bandwidth, and kurtosis. The feasibility of WAFO for non-Gaussian vibration fatigue life prediction and the use of non-Gaussian vibration excitation for accelerated fatigue testing were experimentally verified.

Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Structural Materials ◽  
Fatigue Tests ◽  
Material Defects ◽  
Graphite Cast Iron ◽  
Ultrasonic Fatigue ◽  
Materials Used ◽  
Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

scholarly journals Impacts of Thermal and Mechanical Cycles on Electro-Thermal Anti-Icing System of CFRP Laminates Embedding Sprayable Metal Film

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1589
Author(s):  
Rongjia Li ◽  
Wang Xu ◽  
Dalin Zhang
Keyword(s):  
Fatigue Life ◽  
Metal Film ◽  
Fatigue Testing ◽  
Aerodynamic Force ◽  
Testing Machine ◽  
Laminated Composite ◽  
Heating Element ◽  
Electric Resistance ◽  
Potential Threat ◽  
Mechanical Cycling

The aircraft electro-thermal anti-icing system that can guarantee flight safety may be affected by periodic heating and cyclic aerodynamic force during long-term flight missions, which seems to be a potential threat to ice protection. This paper aims to investigate the impacts of thermal and mechanical cycles on heating elements of the electro-thermal anti-icing system. Specimens were manufactured with CFRP (carbon fiber reinforced polymer) laminated composite, glass fiber prepreg and copper screen, in which sprayable metal film (SMF) was embedded as the heating element. The study focuses on electric resistance variation of SMF and functional fatigue life under the cycling load. Thermal cycling tests were carried out in an insulated chamber where the specimens were heated up to 80 °C and then cooled down to −55 °C for 1000 cycles. Mechanical cycling tests were conducted on a fatigue testing machine where the specimens were imposed on tension-compression loading for 106 cycles. Results showed that the electric resistance of SMF increased with the number of loading cycles. The resistance was increased by 20% and the heating power was decreased by 16.67% after 1000 thermal cycles. During the mechanical cycling tests, it was found that the heating element was destructed before the structural failure, which indicated that the fatigue life of function was lower than that of the structure.

Numerical investigation of the effect of hole reaming on fatigue life by cold expansion

2022 ◽  
Author(s):  
Kuanyu Liu ◽  
Xinsheng Yang ◽  
Li Zhou ◽  
Ming Li ◽  
Weijin Zhu
Keyword(s):  
Fatigue Life ◽  
Fatigue Tests ◽  
Stress Fields ◽  
Analysis Software ◽  
Fe Method ◽  
Alloy Plate ◽  
Cold Expansion ◽  
Hole Edge ◽  
Aluminum Alloy Plate ◽  
The Relationship

The reaming process of the 6061 aluminum alloy plate after cold expansion with split sleeve was simulated by finite element (FE) method based on Abaqus/CAE, the relationship between the reaming depths and the distribution of residual stress fields is obtained by analysis. The fatigue lives of the plate under different reaming depths were calculated by using the fatigue analysis software FE-SAFE, and verified by fatigue tests. The results show that reaming after expansion will increase the residual compressive stress at the hole edge on the entrance surface. In addition, the fatigue life of the specimens increases with the increase of the reaming depth, and the best fatigue gain of the specimen is obtained when the reaming depth of 0.5 mm.

Effect of Slag Composition on Fatigue Life of High Speed Wheel Steel

2013 ◽  
Vol 675 ◽  
pp. 264-269
Author(s):  
Yu Tang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Oxide Inclusion ◽  
Wheel Steel ◽  
Al2o3 Content ◽  
Confocal Laser ◽  
Composition Analysis ◽  
In Situ Observation

In order to improve fatigue life of wheel steel, secondary-refining process was done with Al-deoxidation and slag of high basicity, high Al2O3 content and low oxidizing property. By morphology observation and composition analysis with FESEM, it is found that during LF-VD process, by slag-steel-inclusion interaction, Al2O3 inclusions could transform to MgO-Al2O3 spinel, and later on to CaO-MgO-Al2O3 inclusions, which are inclined to be eliminated by floatation, lowering T[O] content to 0.0007%, enhancing fatigue life of wheel steel. By In-Situ observation with CONFOCAL laser scanning microscope, it is found that MnS precipitates during solidification process, which would core oxide inclusion to form MnS-oxide complex inclusion, contributing to fatigue life improvement of wheel steel. By INSTRON fatigue testing machine, it is found that by successful inclusion control, tested samples achieve ultra-high cycle of 108 above, realizing experimental purpose of improving fatigue life of wheel steel, boosting domestic production process of CRH high speed wheel steel.

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