scholarly journals Improvement of rubber recipe for massive tires by addition of non-traditional fillers

Author(s):  
I. A. Litvinova ◽  
I. V. Veselov ◽  
Y. A. Gamlitskiy

We investigated the effect of new fillers on the properties of rubbers for solid tires. Modified by fullerenes and unmodified iron oxide fillers were used as new fillers. Fatigue characteristics were determined by two methods: multiple tension on the UR-500 device in accordance with GOST 261-79; alternating bending with rotation on the device SZPI in accordance with GOST 10952-75. The main tasks of constructing fatigue curves were to assess the compliance of the results of strength tests (tension at a constant speed to break) with fatigue in terms of fatigue life, fatigue strength, and fatigue energy density of fracture. In addition, the task was to verify the possibility of plotting on one Weller curve points obtained on different devices - UR 500 and ZPI. The ranking of rubbers in static does not coincide with each other. Since the fatigue loading conditions are closer to the actual operating conditions than the static ones, in order to predict the behavior of rubber goods in operation, one should focus on the results of fatigue tests. Combining the results of fatigue tests with repeated tension and with alternating bending with rotation showed that this procedure is valid, but only in cases where the temperature of self-heating on the ZPI device does not exceed a certain critical value when thermal decomposition begins. The results of fatigue tests showed that the use of the studied fillers with small degrees of filling (up to 30 mass parts) can be justified. An example is Ferrocolor fraction 0–20 ?m with a mass fraction of 5 m.h. In this case, the fatigue properties practically do not deteriorate in comparison with industrial rubber for solid tires, in which new fillers are not added.

2007 ◽  
Vol 539-543 ◽  
pp. 4944-4949 ◽  
Author(s):  
Tae Kwon Ha ◽  
Hwan Jin Sung

Thermal fatigue is a complex phenomenon encountered in materials exposed to cyclically varying temperatures in the presence or absence of external load. Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require immediate investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 304 and 429EM stainless steels have been evaluated in the temperature ranges of 200-800oC and 200-900oC. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Thermal fatigue property of STS 304 was superior to that of STS 429EM. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1915
Author(s):  
Jungsub Lee ◽  
Sang-Youn Park ◽  
Byoung-Ho Choi

In this study, the fatigue characteristics of aluminum alloys and mechanical components were investigated. To evaluate the effect of forging, fatigue specimens with the same chemical compositions were prepared from billets and forged mechanical components. To evaluate the cleanliness of the aluminum alloys, the cross-sectional area of specimens was observed, and the maximum inclusion sizes were obtained using extreme value statistics. Rotary bending fatigue tests were performed, and the fracture surfaces of the specimens were analyzed. The results show that the forging process not only elevated the fatigue strength but also reduced the scatter of the fatigue life of aluminum alloys. The fatigue characteristics of C-specimens were obtained to develop finite-element method (FEM) models. With the intrinsic fatigue properties and strain–life approach, the FEM analysis results agreed well with the test results.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1197 ◽  
Author(s):  
Andrzej Kurek

In this study, 16Mo3 steel was analysed for fatigue tests under tension-compression and oscillatory bending conditions. The analysis involved a comparison of fatigue test results obtained using the Manson-Coffin-Basquin, Langer and Kandil models and the models proposed by Kurek-Łagoda. It was observed that it is possible to substitute the basic tension-compression test performed in large testing machines with oscillatory bending tests carried out on a simple, modern test stand. The tests were performed under oscillatory bending on a prototype machine. The testing of 16Mo3 steel proved that the best-known Mason-Coffin-Basquin fatigue characteristic describes the results of all of the experimental tests very well, but the model can only be used when it is possible to divide strains into elastic and plastic components. It should be emphasised here that there is no such possibility in the case of tests performed under oscillatory bending conditions. It was proven that the proposed test method can substitute the tension-compression test very well and be a much more cost efficient way to obtain LCF material fatigue properties.


2018 ◽  
Vol 165 ◽  
pp. 08002 ◽  
Author(s):  
Hamza Lamnii ◽  
Moussa Nait-Abdelaziz ◽  
Georges Ayoub ◽  
Jean-Michel Gloaguen ◽  
Ulrich Maschke ◽  
...  

Polymers operating in various weathering conditions must be assessed for lifetime performance. Particularly, ultraviolet (UV) radiations alters the chemical structure and therefore affect the mechanical and fatigue properties. The UV irradiation alters the polymer chemical structure, which results into a degradation of the mechanical and fatigue behavior of the polymer. The polymer properties degradation due to UV irradiation is the result of a competitive process of chain scission versus post-crosslinking. Although few studied investigated the effect of UV irradiation on the mechanical behaviour of thermoplastics, fewer examined the UV irradiation effect on the fatigue life of polymers. This study focuses on investigating the effect of UV irradiation on the fatigue properties of bulk semi-crystalline polymer; the low density Polyethylene (LDPE). Tensile specimens were exposed to different dose values of UV irradiation then subjected to fatigue loading. The fatigue tests were achieved under constant stress amplitude at a frequency of 1Hz. The results show an important decrease of the fatigue limit with increasing absorbed UV irradiation dose.


2014 ◽  
Vol 598 ◽  
pp. 13-19
Author(s):  
Ewelina Böhm ◽  
Tadeusz Łagoda

The paper presents an analysis of aluminium and its alloys in terms of fatigue strength. The paper contains information in terms of cyclic fatigue tests of aluminium alloys. On the basis of available literature data, Basquin fatigue characteristics have been designated. On their basis a comparison between chosen fatigue characteristics of aluminium alloys with different chemical composition and element percentage in the substance have been done.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yuanxun Zheng ◽  
Kuan Li ◽  
Mengen Ji ◽  
Ehsan Moshtagh

In this paper, the whole life cycle (failure-reinforcement-failure) durability and related fatigue properties of prestressed hollow beam under carbonation erosion environment were studied. According to a 20 m hollow slab beam, the model of prestressed hollow beam was designed and made, and the durability and fatigue tests for the whole life cycle of prestressed hollow beam were carried out. The results showed that the compressive strength and elastic modulus of the specimens increased by about 20% under the action of carbonization erosion. With the increase of fatigue loading cycles, the crack occurrence and development speed of carbonized erosion components were greater than those of healthy components, and the fatigue life decreased sharply from 3 million cycles to 50,000 cycles. Pasting carbon fiber and steel plate had better reinforcement effect on the damaged prestressed plate beam and could help improving the fatigue life of the reinforced component. Comparing the reinforcement of different strengthening methods, it is found that the steel-plate-reinforced components have better mechanical properties and antifatigue attenuation characteristics than the carbon-fiber-reinforced ones. The research results have important theoretical value for improving the durability of structure and prolonging its service life.


2011 ◽  
Vol 465 ◽  
pp. 531-534 ◽  
Author(s):  
Stefano Beretta ◽  
Mauro Filippini ◽  
Luca Patriarca ◽  
Giuseppe Pasquero ◽  
Silvia Sabbadini

The fatigue properties of a Ti-48Al-2Cr-2Nb alloy obtained by electron beam melting (EBM) with a patented process has been examined by conducting high cycle fatigue tests performed at different loading ratios both at room temperature and at high temperatures, comparable to those experienced by the components during service. Some tests have been conducted in the superlong life regime well exceeding 10 million cycles, highlighting individual fatigue characteristics of the studied TiAl alloy.


1957 ◽  
Vol 8 (1) ◽  
pp. 1-20 ◽  
Author(s):  
N. E. Frost

SummaryReversed direct stress and rotating bending fatigue tests have been carried out on Vee-notched specimens of aluminium alloy, nickel chromium steel and mild steel.Diagrams are presented showing the relationship between the geometric stress concentration factor Kt and the strength reduction factor Kt. It was found that non-propagating cracks formed in the roots of the sharper notches. These cracks formed at or above some critical value of Kt, the value depending on the specimen material. Below the critical value of Kt, cracks did not form unless the applied nominal stress exceeded that at the fatigue limit, and a crack, once formed, continued to propagate until the specimen failed. Above the critical value of Kt, non-propagating cracks formed at nominal stresses less than the fatigue limit, the stress having to be increased to the latter value in order to propagate the crack. This critical value of Kt coincided with the maximum Kf value realised. It would appear that Kf equals Kt up to a certain value of Kt; there is then a transition where Kt reaches a maximum at the critical value of Kt. Increasing the value of Kt above the critical value causes no further increase and may tend to decrease the value of Kt.The conclusions drawn apply only when the fatigue stresses are completely reversed, i.e. the mean load is zero.


2013 ◽  
Vol 592-593 ◽  
pp. 594-597 ◽  
Author(s):  
Aleksander Karolczuk ◽  
Mateusz Kowalski

Structure of bimetallic composite obtained during explosive welding process exhibits strong heterogeneity in the vicinity of interface. The interface usually has a wavy shape with characteristic increase of hardness and largely deformed grains. Recently obtained fatigue tests for titanium-steel bimetal specimens under fully reversed push-pull loading show ratcheting phenomenon. In order to investigate this phenomenon mechanical testing and structural observations of titanium-steel bimetal and titanium before cladding have been performed. Fatigue characteristics in the form of relation between strain amplitude and fatigue life for titanium (Grade 1), steel (S355J2+N) and bimetal will be presented.


2018 ◽  
Vol 47 (4) ◽  
pp. 335-341
Author(s):  
Juraj Belan ◽  
Lenka Kuchariková ◽  
Eva Tillová ◽  
Denisa Závodská ◽  
Mária Chalupová

In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. If the loads are above a certain threshold, microscopic cracks will begin to form at the stress concentrators such as the surface, persistent slip bands (PSBs), interfaces of constituents in the case of composites, and grain interfaces in the case of metals. Eventually a crack will reach a critical size, the crack will propagate suddenly, and the structure will fracture. The first works about fatigue phenomenon were published since 1837 and intensively was investigated by Wöhler in 1860. With needs of using the progressive materials such titanium and Ni-base superalloys become more significant to put under the various fatigue loading these sorts of alloys. Presented article deals with how the various condition of loading influenced an IN718 alloy fatigue lifetime especially. The fatigue tests provided on this kind of material was done via low frequency loading and push-pull or rotation-bending stress up to this time. Fatigue tests of experimental material was carried out at two different frequencies, 20 kHz with stress ration R = - 1 (push – pull, σm = 0 MPa) as well as the three-point bending load R ˂ 1 (σom = 526.8 MPa) at low frequency 150 Hz at room temperature. The microstructure characterization and Scanning Electron Microscopy (SEM) fractography analysis of fatigue process were done as well. The main goal of study was analyze obtained data after fatigue test and consider, if the various loading modes have influence on fatigue lifetime (initiation sites, crack propagation character, etc.).


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