The Mechanical Behavior of Short-Fiber-Elastomer Composites

1976 ◽  
Vol 49 (5) ◽  
pp. 1167-1181 ◽  
Author(s):  
A. Y. Coran ◽  
P. Hamed ◽  
L. A. Goettler

Abstract The measured elastic and strength properties of angle-ply composites of short fibers and rubber depend on test-piece geometry. In general, higher tensile moduli and strengths are obtained when plies are both thin and wide. Once the effects of test-piece geometry are taken into account, elastic properties can be calculated as functions of the properties of a single ply. Classical compliance transformation equations can be used. However, because of the invariance of shear modulus in aligned composites, the tensor transformation equations are somewhat simplified. Tensile strengths of off-axis unidirectional composite plates and balanced-angle plies can be fitted by Hill's criterion. Unidirectional composites tend to fail in the weakest mode, depending on the angle of stress, but laminating causes all principal stresses in a ply to be near their ultimate limit at the time of failure.

2011 ◽  
Vol 243-249 ◽  
pp. 4182-4187
Author(s):  
Zhi Yong Ding ◽  
Jing Liang Dai ◽  
Bo Peng

after reasonably analyzing characteristics of flexible fiber reinforcement fragile material, the mechanical model of individual fiber is established while being pulled out from asphalt; the spherical coordinates is adopted to establish the calculation model for short fiber bridging stress evenly distributed in space to calculate the value of bridging stress generated by short fibers while asphalt is breaking; the fiber asphalt sample in big size is adopted to perform low temperature tensile failure test to practically measure bridging stress of short fiber; fit the calculated value and measured value of bridging stress by adjusting parameters in the calculation model to check the rationality of fiber bridging stress in calculation method and model.


2013 ◽  
Vol 328 ◽  
pp. 387-392
Author(s):  
Cai Jun Liu ◽  
Chuan Sheng Wang

The mixing mechanism of short fiber/rubber composite was analyzed. The clearance between the rotor edge peak and mixing chamber influenced mixing, dispersion and length of the short fibers in compound. The new rotor was designed with variable clearance. The large clearance gap improve the mixing, and the small clearance gap helped to improve the dispersion of short fiber. The mixing quality and performance of short fiber/rubber composite were improved by using the new rotor, and the production efficiency increased.


TAPPI Journal ◽  
2017 ◽  
Vol 16 (02) ◽  
pp. 89-95
Author(s):  
HEIKKI UPOLA ◽  
ARI AMMALA ◽  
MIRJA ILLIKAINEN

A wide variety of packaging materials with different wetting rates and wet strength properties are used in old corrugated container (OCC) processing. The disintegration rates of the different grades also vary and enable the use of the fractional pulping concept where easily disintegrated material is removed at the early stages. In the present study, fractional drum pulping was studied by pulping (Pilot drum pulping) and fractionating (Tampella oscillating screen) a mixture of strong-grade kraftliner and weak-grade fluting at high consistency to determine if energy consumption could be reduced. The results showed that a 25% energy saving could be realized through fractional pulping and an even higher potential might be possible if pulping conditions are optimized. Average fiber length, fines content, and ash content in the separated fractions were analyzed. The separated short fiber fractions and long fiber fractions could be individually processed, thus decreasing the volumes in the unit processes on the OCC line.


2018 ◽  
Vol 38 ◽  
pp. 02022
Author(s):  
Dewei Zhang ◽  
Chuansheng Wang ◽  
Bo Shen ◽  
Shaoming Li ◽  
Huiguang Bian

In recent years, rubber composites reinforced by short fibers has been researched deeply, because of its good performances such as higher wear resistance, higher cut resistance and so on. Some research results indicated that if short fibers get orientation in rubber composites, the performances of rubber products could be promoted greatly. But how to make short fibers get orientation in rubber matrix during extrusion is still a real problem. And there are many parameters affect the short fibers orientation. So, in this paper, the effects of die structure including expansion-die and dam-expansion-die on extrusion flow field of short fiber and rubber composite material during extrusion process has been researched by Polyflow. And the FEA results about the pressure field, velocity field and the velocity vector of the rubber composites flow field indicate that, comparing with expansion-die and the dam-expansion-die, the latter one is better for the extrusion process of rubber composites and making short fibers get radial orientation in rubber matrix.


2010 ◽  
Vol 50 (1) ◽  
pp. 535 ◽  
Author(s):  
Vamegh Rasouli ◽  
Zachariah Pallikathekathil ◽  
Elike Mawuli

A geomechanics study carried out in the Blacktip field, offshore Australia led to optimum wellbore deviation and azimuth to minimise drilling-associated instability problems near a major fault in the field. Elastic and strength properties of the formations and magnitude of principal stresses in the field were estimated from a mechanical earth model (MEM) based on offset well data. The direction of the minimum horizontal stresses was predicted from formation microresistivity image (FMI) logs available in offset wells. The MEM results were calibrated using results from laboratory experiments, well tests and drilling incidents from drilling reports. The MEM showed that formations at the lower section of the well are very competent and have high uniaxial strength; however, most of the failures in the form of breakouts observed from calliper and image logs were in this interval. Therefore, obtaining a good match between the model and observed failures required a large stress anisotropy to be considered for the lower section of the wellbore. Further investigations demonstrated that this is because the wellbore trajectory at deeper depth gets closer to the major fault plane, and this large stress anisotropy is due to the stress redistribution near the fault. The data from offset well was mapped into the planned trajectory, and the selection of the optimum trajectory and a stable mud weight window for the appropriate section led to successful drilling of the deviated well.


1992 ◽  
Vol 114 (3) ◽  
pp. 358-363 ◽  
Author(s):  
Y. W. Kwon

Effect of microcracks, such as local matrix crack and fiber breakage, on a macroscale crack in a unidirectional composite plate was studied for various fiber volume fractions, as well as different material properties of fiber and matrix materials. A finite element analysis was performed for this study. It showed that microcracks, located near a macroscale crack tip, resulted in a significant increase of stress intensity factor at the crack tip.


2015 ◽  
Vol 3 (37) ◽  
pp. 9684-9694 ◽  
Author(s):  
Yi Zhang ◽  
Zhou Wang ◽  
Boliang Zhang ◽  
Chengjun Zhou ◽  
Guang-Lin Zhao ◽  
...  

C–SiC core–shell short fiber fillers improve the electromagnetic interference shielding effectiveness in polymer composites.


2011 ◽  
Vol 474-476 ◽  
pp. 548-552
Author(s):  
Jun Tian

Constant stress tensile creep tests were conducted on AZ91D–20 vol.%, 25 vol.%, and 30 vol.% Al2O3-SiO2short fiber composites and on an unreinforced AZ91D matrix alloy. The creep resistance of the reinforced materials is shown to be considerably improved compared with the matrix alloy. With the increasing volume fraction of short fibers, the creep resistance of AZ91D composites is improved, and their creep threshold stresses are also increased accordingly. Because of the increasing volume fraction of short fibers, loads of bearing and transmission of short fibers will increase, and thus the creep resistance of AZ91D composites further improves, but the precipitation of β-Mg17Al12precipitate increases in the number, it is easy to soften coarse, so that threshold stress of AZ91D composite does not increase greatly.


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