scholarly journals Influence of mean stress and mean strain on fatigue life of carbon black filled natural rubber

2017 ◽  
pp. 15-22
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Natural Rubber ◽  
Mean Stress ◽  
Mean Strain

Cycle-Dependent Stress Relaxation of A-286 Alloy

1960 ◽  
Vol 82 (3) ◽  
pp. 654-658 ◽  
Author(s):  
A. S. Ross ◽  
JoDean Morrow
Keyword(s):  
Fatigue Life ◽  
Material Behavior ◽  
Mean Stress ◽  
Fatigue Specimen ◽  
Fatigue Data ◽  
The Mean ◽  
Cycle Dependent ◽  
Mean Strain ◽  
Mean Stresses ◽  
Strain Cycling

When an axial fatigue specimen is subjected to repeated strain cycling about a fixed mean strain value, the mean stress decreases with the number of strain cycles. To explore this type of material behavior, tubular fatigue specimens of A-286 alloy have been axially tested under conditions of controlled strain, and the cycle-dependent relaxation of mean stress measured. Fatigue data for five initial mean stresses are also reported. It was found that, in the case of A-286 alloy, most of the relaxation occurred early in the fatigue life, especially during the first ten cycles.

Fatigue Behavior of Stainless Steel 304L Including Strain Hardening, Prestraining, and Mean Stress Effects

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Julie Colin ◽  
Ali Fatemi ◽  
Said Taheri
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Stress Relaxation ◽  
Fatigue Behavior ◽  
Control Mode ◽  
Mean Stress ◽  
Continuous Increase ◽  
Stainless Steel 304L ◽  
Mean Stress Relaxation ◽  
Mean Strain

This paper discusses cyclic deformation and fatigue behaviors of stainless steel 304L and aluminum 7075-T6. Effects of loading sequence, mean strain or stress, and prestraining were investigated. The behavior of aluminum is shown not to be affected by preloading, whereas the behavior of stainless steel is greatly influenced by prior loading. Mean stress relaxation in strain control and ratcheting in load control and their influence on fatigue life are discussed. Some unusual mean strain test results are presented for SS304L, where in spite of mean stress relaxation fatigue lives were significantly longer than fully-reversed tests. Prestraining indicated no effect on either deformation or fatigue behavior of aluminum, while it induced considerable hardening in SS304L and led to different results on fatigue life, depending on the test control mode. Possible mechanisms for secondary hardening observed in some tests, characterized by a continuous increase in the stress response and leading to runout fatigue life, are also discussed. The Smith–Watson–Topper parameter was shown to correlate most of the experimental data for both materials under different loading conditions.

Biaxial Fatigue Testing Of Vulcanizates

1961 ◽  
Vol 34 (2) ◽  
pp. 506-526 ◽  
Author(s):  
S. D. Gehman ◽  
P. Rohall ◽  
D. I. Livingston
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Natural Rubber ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Biaxial Fatigue ◽  
Wide Range ◽  
Different Types ◽  
Extreme Probability ◽  
General Service

Abstract Extensive fatigue tests of vulcanizates of natural rubber and SBR were carried out using a cycle of alternate stretching in two perpendicular directions. It is shown that the data can be best handled statistically by assuming a lognormal distribution or by the use of extreme probability techniques. Illustrative results are given to compare the fatigue life of different types of SBR ; to show the value of the method for studying the effects of processing variations on fatigue life ; to determine the effect of various loadings of different types of carbon black; and to evaluate the effectiveness of anitoxidants and antiozonants. Exploratory tests using ozone instead of pinholes to initiate the failure eliminated the wide range in fatigue life between natural rubber and SBR, and in this respect gave a result which is more consistent with general service experience. This type of biaxial fatigue testing has many areas of usefulness for developing good endurance qualities in vulcanizates.

Carbon black grade influence on strain controlled fatigue life of natural rubber

2019 ◽  
pp. 439-444
Author(s):  
J.M. Pilarski ◽  
J.R. Goossens ◽  
W.V. Mars ◽  
C.G. Robertson
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Natural Rubber

Influence of Mean Strain on Fatigue Life of Stainless Steel (Effect of Constant and Ratcheting Mean Strain)

2014 ◽  
Author(s):  
Masayuki Kamaya
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Effective Strain ◽  
Mouth Opening ◽  
Strain Range ◽  
Fatigue Tests ◽  
Mean Stress ◽  
Crack Mouth ◽  
The Mean ◽  
Mean Strain

The influence of mean strain on fatigue life was investigated for Type 316 stainless steel at room temperature in ambient environment. Two types of mean strain were simulated in the fatigue tests: constant and increasing (ratcheting) mean strains. In order to apply the constant mean strain, prestraining was induced prior to fatigue tests. Although the stress amplitudes became larger due to the prestraining, fatigue lives were almost the same as those obtained using non-prestrained specimens for the same strain range. Change in the maximum peak stress and stress amplitude due to the prestraining had little influence on the fatigue life. It was shown that the mean strain showed little influence on the fatigue life under the same strain range. The ratcheting mean strain was observed during the fatigue tests under mean stress. The fatigue life was reduced by applying the mean stress for the same strain range. The degree of the reduction was increased with the magnitude of the ratcheting mean strain. It was deduced that the increasing mean strain enhanced the crack mouth opening and increased the effective strain range. It was concluded that the ratcheting mean strain reduced the fatigue life for the same strain range, and the reduction in fatigue life could be predicted conservatively by assuming the crack mouth was never closed during the fatigue tests.

Study on the effect of virgin and recycled chloroprene rubber (vCR and rCR) on the properties of natural rubber/chloroprene rubber (NR/CR) blends

2013 ◽  
Vol 33 (9) ◽  
pp. 803-811 ◽  
Author(s):  
Siti Z. Salleh ◽  
Hanafi Ismail ◽  
Zulkifli Ahmad
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Carbon Black ◽  
Natural Rubber ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Constant Content ◽  
Cure Time ◽  
Chloroprene Rubber ◽  
Minimum Torque

Abstract The effects of various ratios of virgin chloroprene rubber (vCR) and recycled chloroprene rubber (rCR) with a constant content of carbon black (CB) on the properties of natural rubber/chloroprene rubber NR/CR blends were studied. The minimum torque (ML), maximum torque (MH), scorch time, and cure time increased with the addition of both CRs and the effects of rCR were more pronounced than vCR on these properties. The tensile strength and fatigue life of the NR/vCR blends increased with an addition of vCR up to 25 phr and then decreased with a higher vCR. However, NR/rCR blends reflected otherwise for both properties. The elongation at break and swelling percentage of NR/CR blends decreased with the addition of both vCR and rCR.

Curing Characteristics, Fatigue Life and Morphological Properties of Natural Rubber Nanocomposites with Halloysite Nanotubes (HNTs)/Carbon Black (CB) Hybrid Filler

2011 ◽  
Vol 471-472 ◽  
pp. 957-962 ◽  
Author(s):  
Siti Zuliana Salleh ◽  
Hanafi Ismail ◽  
Zulkifli Ahmad
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Natural Rubber ◽  
Halloysite Nanotubes ◽  
Filler Loading ◽  
Morphological Properties ◽  
Hybrid Filler ◽  
Curing Characteristics ◽  
Roll Mill ◽  
Cure Time

In this research, natural rubber (NR) with halloysite nanotubes(HNTs)/carbon black (CB) hybrid filler at various filler loading was investigated where the total filler loading used in each compound were 40 phr. The curing characteristics, fatigue life and morphological properties of HNTs/CB/NR nanocomposites were studied. Laboratory two-roll mill was used for mixing process. The results revealed that vulcanizates containing more HNTs in hybrid filler exhibit longer scorch time (ts2) and cure time (t90) for curing characteristics and higher in fatigue life compared to vulcanizates with 40 phr of CB. The images from scanning electron microscope (SEM) confirmed that replacement of carbon black with halloysite nanotubes improved the fatigue life by showing more tearing surface on vulcanizates.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

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