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

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

2010 ◽  
Vol 168-170 ◽  
pp. 488-491
Author(s):  
Jin Rong Wu

The fatigue behavior of the asphalt mixtures beams is experimented by sine wave load, and the fatigue life is predicted by ultrasonic ware theories. Test results show that ultrasonic ware can reflect better fatigue process, and it is an effective method to analyze and forecast fatigue property.


2016 ◽  
Vol 62 (1) ◽  
pp. 83-98 ◽  
Author(s):  
A. Szydło ◽  
K. Malicki

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.


1958 ◽  
Vol 62 (570) ◽  
pp. 456-457 ◽  
Author(s):  
M. Fine

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.


2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu

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.


2020 ◽  
Vol 398 ◽  
pp. 54-59
Author(s):  
Nisreen Mizher Rahma ◽  
Lubna Ghalib ◽  
Khalid Mershed Eweed

This study presents the experimental results of the influence of mechanical fatigue and tensile on hybrid composite materials. Epoxy with Novolac resin are used as matrix for the reinforced materials that consist of glass fiber type E. The slates made of hybrid composite materials for two proportions (80% epoxy, 20% Novolac) and (60% epoxy, 40% Novolac) were reinforced by three volume fractions (10%, 20% and 30%) of glass fiber type (E), where been manufacturing (6) panels of hybrid composite materials, all these panels cutting into two groups samples with dimension (70x 10) mm in order to execute the fatigue test and (150x20) mm for tensile test, according to the specifications of the device used.The process took place in two stages: The two stages include executing the fatigue and tensile test specimens with a ratio (80% epoxy, 20% Novolac) in the first stage and (60% epoxy, 40% Novolac) in the second stage for the volume fractions (10%, 20% and 30%) of glass fiber type (E) and comparison the results between them for each stage. The results obtained from fatigue test in the first stage showed that the number cycle for fatigue limit decreased when the load and the number of layers of reinforcing are increased. But in the tensile test for the samples the results showed that the value of the elongation increasing to the point of failure when the load increased for the same layers of reinforcement, as well as the value of elongation decreasing to a failure when increased the number of layers of reinforcing glass fibers type (E) for the same load. The results of tensile and fatigue test obtained from the second stage showed similar to the results in the first stage, but the cycle number of fatigue limit less value from the first stage and the stress was higher in the fatigue test. For tensile test the elongation values ​​less and the stress values higher for the same volume fraction of the reinforcement due to increase in the proportion of Novolac.


2010 ◽  
Vol 654-656 ◽  
pp. 2583-2586
Author(s):  
Hee Young Ko ◽  
Kwang Bok Shin ◽  
Jung Seok Kim

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.


Author(s):  
D. Rozumek ◽  
Z. Marciniak

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.


2008 ◽  
Vol 33-37 ◽  
pp. 163-168 ◽  
Author(s):  
Jun Deng ◽  
Marcus M.K. Lee ◽  
Pei Yan Huang

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.


2012 ◽  
Vol 236-237 ◽  
pp. 38-42 ◽  
Author(s):  
Yong Chun Cheng ◽  
Hui Li Ma ◽  
Qing Lin Guo ◽  
Chun Xu ◽  
Peng Zhang

Diatomite and glass fiber are used for modifying asphalt concrete in this paper. Besides, wet and dry processes are adopted to achieve the composite modified asphalt concrete. Meanwhile, experimental investigation has been done on its fatigue properties and dynamic mechanical property, it indicates that diatomite-glass fiber modified asphalt concrete has a better capacity to resist fatigue damage. Compared with matrix asphalt concrete, the modified asphalt concrete has higher fatigue life. Thus, its mechanical parameter of fatigue property changes obviously so as to provide a reference basis for the durability design of pavement materials.


2009 ◽  
Vol 413-414 ◽  
pp. 757-764 ◽  
Author(s):  
Cheng Ming Lan ◽  
Hui Li

Based on fatigue test results of corroded wires obtained from dissection of actual parallel wire cables which were used on a certain domestic cable-stayed bridge, the fatigue properties of corroded parallel wire cable are investigated by the method of Monte Carlo simulation in this paper. The results of fatigue life and corrosion degree of corroded wire are presented. Comparisons between the original design information and fatigue test results, it can be seen that corrosions make the fatigue lives of wires decreasing sharply. The fatigue life of individual wire is described by Weibull distribution considered some useful parameters such as, stress range, mean stress, mean static strength and length effects. The effects of percentage of broken wire, cable S-N curve parameter on cable fatigue life are discussed. It can be seen that the cable fatigue lives are controlled by a small fraction of the cable wires with the shortest fatigue lives. Finally, the S-N curves of cable are calculated by Monte Carlo simulations based on the results of individual wire fatigue test, and compared with the results of cable fatigue test.


Sign in / Sign up

Export Citation Format

Share Document