A Study on Improvement of Fatigue Life for Woven Glass Fabric/Epoxy Laminate Composite Applied to Railway Vehicle

2010 ◽  
Vol 654-656 ◽  
pp. 2583-2586
Author(s):  
Hee Young Ko ◽  
Kwang Bok Shin ◽  
Jung Seok Kim
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Laminate Composite ◽  
Glass Fabric ◽  
Railway Vehicle ◽  
Test Results ◽  
Laminate Composites ◽  
Remarkable Improvement ◽  
Fatigue Characteristics

In this study, the fatigue characteristics and life of woven glass fabric/epoxy laminate composites applied to railway vehicle were evaluated. The fatigue test was conducted by tension-tension load with stress ratio R of 0.1 and frequency of 5Hz. The material used to fatigue test was two types of woven glass fabric/epoxy laminate composite with and without the reinforcement of carbon/epoxy ply. Also, the fatigue life of woven glass fabric/epoxy laminate composite was compared with that of aluminum 6005 used to the car-body and under-frame structures of railway vehicle. The test results showed that the failure strength and life of woven glass fabric/epoxy laminate composite with the reinforcement of three carbon/epoxy plies had a remarkable improvement in comparison with that of bare specimen without reinforcement.

scholarly journals Analysis of the Correlation between the Static and Fatigue Test Results of the Interlayer Bondings of Asphalt Layers

2016 ◽  
Vol 62 (1) ◽  
pp. 83-98 ◽  
Author(s):  
A. Szydło ◽  
K. Malicki
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Mixture ◽  
Fatigue Tests ◽  
Test Results ◽  
Static Tests ◽  
Bonding State ◽  
Road Pavement ◽  
The Future ◽  
Pavement Structure

Abstract The bonding state of the asphalt layers in a road pavement structure significantly affects its fatigue life. These bondings, therefore, require detailed tests and optimization. In this paper, the analyses of the correlation between the results of laboratory static tests and the results of fatigue tests of asphalt mixture interlayer bondings were performed. The existence of the relationships between selected parameters was confirmed. In the future, the results of these analyses may allow for assessment of interlayer bondings’ fatigue life based on the results of quick and relatively easy static tests.

scholarly journals Fatigue Life Prediction of Rolling Bearings Based on Modified SWT Mean Stress Correction

2020 ◽  
Author(s):  
Aodi Yu ◽  
Hong-Zhong Huang ◽  
Yan-Feng Li ◽  
He Li ◽  
Ying Zeng
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Stress Ratio ◽  
Prediction Models ◽  
Great Influence ◽  
Sensitivity Coefficient ◽  
Model Verification ◽  
Mean Stress ◽  
Test Results ◽  
Rolling Bearings

Abstract Mean stress has a great influence on fatigue life, commonly used stress-based life prediction models can only fit the test results of fatigue life under specific stress ratio or mean stress but cannot describe the effect of stress ratio or mean stress on fatigue life. Smith, Watson and Topper (SWT) proposed a simple mean stress correction criterion. However, the SWT model regards the sensitivity coefficient of all materials to mean stress as 0.5, which will lead to inaccurate predictions for materials with a sensitivity coefficient not equal to 0.5. In this paper, considering the sensitivity of different materials to mean stresses, compensation factor is introduced to modify the SWT model, and several sets of experimental data are used for model verification. Then, the proposed model is applied to fatigue life predictions of rolling bearings, and the results of proposed method are compared with test results to verify its accuracy.

scholarly journals Study of Fatigue and Bending Properties For Epoxy / Kevlar - Glass Fibers and Hybrid Composite

2014 ◽  
Vol 11 (2) ◽  
pp. 540-546
Author(s):  
Baghdad Science Journal
Keyword(s):  
Fatigue Life ◽  
Glass Fiber ◽  
Fatigue Test ◽  
Hybrid Composite ◽  
Glass Fibers ◽  
Fatigue Property ◽  
Test Results ◽  
Kevlar Fiber ◽  
Prepared Material ◽  
Better Than

In this research a study of the effect of quality, sequential and directional layers for three types of fibers are:(Kevlar fibers-49 woven roving and E- glass fiber woven roving and random) on the fatigue property using epoxy as matrix. The test specimens were prepared by hand lay-up method the epoxy resin used as a matrix type (Quick mast 105) in prepared material composit . Sinusoidal wave which is formed of variable stress amplitudes at 15 Hz cycles was employed in the fatigue test ( 10 mm )and (15mm) value 0f deflection arrival to numbers of cycle failure limit, by rotary bending method by ( S-N) curves this curves has been determined ( life , limit and fatigue strength) of composite . The results show us the reinforcement has important act to increased resistance to the fatigue compared with specimens have non reinforcement this side the specimens reinforcement of glass fiber have resistance to fatigue and fatigue life better than the specimens reinforcement of Kevlar fiber . According to hybrid composite sample fatigue test results showed that the sample which reinforced (Kevlar - regular glass – Kevlar) has a best results which showed stress carrying the most powerful and longer fatigue life with more than (1.3 ×10 6) cycle from other hybrids , while the sample with the sample with three Kevlar reinforced layers have less resistant to fatigue

A Standardised Method of Representing Fatigue Test Results

1958 ◽  
Vol 62 (570) ◽  
pp. 456-457 ◽  
Author(s):  
M. Fine
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Test Results ◽  
Flat Part

Figure 1 is a set of S-N curves for DTD. 150, taken from Rotol Structures Department Report No. 337. It is difficult to estimate N accurately on the flat part of the curve, and estimates of fatigue life by different people can be very different. Fig. 1, although based on scanty test results, is typical of S-N curves.

Fatigue Performance of Concrete with Pre-Cracks in Tension-Compression Cycles

2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Compression Cycle

A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

Crack growth of explosive welding zirconium-steel bimetal subjected to cyclic bending

2017 ◽  
Author(s):  
D. Rozumek ◽  
Z. Marciniak
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Fatigue Test ◽  
Cross Section ◽  
Explosive Welding ◽  
Test Results ◽  
Cyclic Bending ◽  
Interaction Mechanisms ◽  
Melted Layer

The paper presents the fatigue test results including the cracks growth in the composite zirconium-steel subjected to oscillatory bending. Specimens of square cross-section without melted layer and with a melted layer were tested. In the specimens the net ratio of thickness of steel to zirconium layers was h1 : h2 = 2.5 : 1. It was observed that a higher fraction of the intermetallic inclusions near the interface increase the fatigue life. Two different interaction mechanisms between a crack and interface were observed.

Fatigue Life Calculation in Conditions of Wide Spectrum Random Loadings – The Experimental Verification of a Calculation Algorithm on the Example of 41Cr4 Steel

2012 ◽  
Vol 726 ◽  
pp. 17-26
Author(s):  
Bogdan Ligaj ◽  
Grzegorz Szala
Keyword(s):  
Fatigue Life ◽  
Wide Spectrum ◽  
Loading Conditions ◽  
Test Results ◽  
Structural Elements ◽  
Random Loading ◽  
Calculation Algorithm ◽  
Fatigue Characteristic ◽  
Life Tests ◽  
Fatigue Characteristics

Precision of fatigue life calculations of structural elements in programmed loading conditions is connected with proper elaboration of loading spectrum and assumption of a proper fatigue characteristic. On the base of literature data and own research there has been elaborated an algorithm for fatigue life calculations in random loading conditions with wide spectrum. Calculations were performed with the usage of chosen mathematical models of two-parametric fatigue characteristics. Results calculated with accordance to the described procedure were validated with experimental test results of specimens made of 41Cr4 steel with a method of programmed fatigue life tests.

Experimental Study on Fatigue Life of Steel Beams Strengthened with a CFRP Plate

2008 ◽  
Vol 33-37 ◽  
pp. 163-168 ◽  
Author(s):  
Jun Deng ◽  
Marcus M.K. Lee ◽  
Pei Yan Huang
Keyword(s):  
Fatigue Life ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Fatigue Test ◽  
Interfacial Stress ◽  
Steel Beams ◽  
Test Results ◽  
Load Range ◽  
Cfrp Plate ◽  
Crack Initiation Life

The adhesive bonding between the steel beam and carbon fibre reinforced polymer (CFRP) plate is the weakest link and fatigue performance is a major consideration. This paper gives details of a fatigue test programme of a series of small-scale steel beams bonded with a CFRP plate. Two phases of the fatigue life, including crack initiation life and crack propagation life, are considered. Backface-strain technique was applied to monitor crack initiation. An S-N curve was developed from the test results. The curve correlates the maximum principal interfacial stress at the plate end to the crack initiation life. The fatigue limit of the S-N curve was found to be about 30% of the ultimate static failure stress. In accordance with Paris Law, moreover, an equation was developed to predict the number of cycles during the crack propagation. The empirical coefficients of the equation were obtained from the fatigue test results. This equation can correctly predict the crack propagation life. The fatigue load range affects the fatigue life, but its significance is much less than the magnitude of the maximum load in the load range.

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