Rubber Fracture Characterization Using J-Integral

1988 ◽  
Vol 16 (1) ◽  
pp. 44-60 ◽  
Author(s):  
C. L. Chow ◽  
J. Wang ◽  
P. N. Tse

Abstract The use of the J-integral to investigate fracture characterization in a carbon black reinforced natural rubber is described. Three applications to crack initiation are included: two based on the use of a hypothetical zero specimen length and one on conventional testing procedures for metals. While the validity of the zero-length methods is questionable, the conventional method yielded a consistent Jc value of 1.01 N/mm for a typical tire compound. This value was obtained from 24 combinations of varying specimen geometries and pre-crack lengths. The J-integral is revealed as a valid fracture parameter that is applicable not only for material evaluation but also for designing tire structures to resist premature failure. These conclusions disagree with those from an earlier investigation, so the causes for the discrepancies are examined and discussed.

1986 ◽  
Vol 59 (5) ◽  
pp. 787-799 ◽  
Author(s):  
R. F. Lee ◽  
J. A. Donovan

Abstract 1. Evaluation of ∫σdδ where σ is the net section stress and δ is the deformed crack tip diameter requires only one specimen to characterize the initiation of crack growth in unfilled and carbon-black-filled NR. 2. ∫σdδ is equal to one half of the J-integral for crack growth initiation, which is identical to the Thomas tearing energy for a blunt notch. 3. The critical J-integral for crack initiation increases linearly with carbon black content. 4. The critical crack tip radius for crack initiation is independent of carbon black content, and the required crack tip region stress increases linearly with carbon black content.


2016 ◽  
Vol 89 (1) ◽  
pp. 126-141 ◽  
Author(s):  
Bertrand Huneau ◽  
Isaure Masquelier ◽  
Yann Marco ◽  
Vincent Le Saux ◽  
Simon Noizet ◽  
...  

ABSTRACT A detailed study of the initiation of fatigue cracks in carbon black–filled natural rubber is conducted. Interrupted fatigue tests are performed and fatigued samples are observed with a scanning electron microscope. This procedure first enables the quantification of the morphology, spatial distribution, and evolution of crack initiation sites for different strain levels, which gives some statistical data for each strain level. It also permits analysis of the chemical nature of inclusions inducing crack initiation thanks to energy dispersive spectrometry of X-rays. It is shown that fatigue damage initially occurs generally on carbon black agglomerates or oxides such as ZnO. However, those two types of inclusions correspond to different crack initiation mechanisms, and most of the time, only the initiations on carbon black agglomerates are followed by crack propagation that leads to failure. This difference is probably because carbon black agglomerates have a stronger cohesion than ZnO inclusions and a stronger adhesion to the matrix.


1987 ◽  
Vol 60 (4) ◽  
pp. 674-688 ◽  
Author(s):  
R. F. Lee ◽  
J. A. Donovan

Abstract For PS and SEN specimens: 1) Jδ (one half Jθ) can be determined from one specimen and is independent of crack size and specimen geometry. 2) J and T at initiation differed. 3) J at initiation increased with carbon black content, but the critical crack-tip radius did not.


Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1098
Author(s):  
Jibin Keloth Paduvilan ◽  
Prajitha Velayudhan ◽  
Ashin Amanulla ◽  
Hanna Joseph Maria ◽  
Allisson Saiter-Fourcin ◽  
...  

Nanomaterials have engaged response from the scientific world in recent decades due to their exceptional physical and chemical properties counter to their bulk. They have been widely used in a polymer matrix to improve mechanical, thermal, barrier, electronic and chemical properties. In rubber nanocomposites, nanofillers dispersion and the interfacial adhesion between polymer and fillers influences the composites factual properties. In the present work, a comparison of the hybrid effects of carbon black with two different nanofillers (graphene oxide and nanoclay) was studied. The 70/30 composition of chlorobutyl rubber/natural rubber elastomer blend was taken as per the blend composition optimized from our previous studies. The hybrid effects of graphene oxide and nanoclay in dispersing the nanofillers were studied mainly by analyzing nanocomposite barrier properties. The results confirm that the combined effect of carbon black with graphene oxide and nanoclay could create hybrid effects in decreasing the gas permeability. The prepared nanocomposites which partially replace the expensive chlorobutyl rubber can be used for tyre inner liner application. Additionally, the reduction in the amount of carbon black in the nanocomposite can be an added advantage of considering the environmental and economic factors.


Author(s):  
Koushik Pal ◽  
Hirak Satpathi ◽  
Tirthankar Bhandary ◽  
Barun Kumar Samui ◽  
Sanjay Bhattacharyya ◽  
...  

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