Mechanical Properties of Short-Fiber-Elastomer Composites

1976 ◽  
Vol 49 (5) ◽  
pp. 1160-1166 ◽  
Author(s):  
S. R. Moghe
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Fiber Orientation ◽  
Fiber Length ◽  
Flow Direction ◽  
Length Distribution ◽  
Fiber Content ◽  
Constant Length ◽  
Composite Stiffness ◽  
Composite Properties

Abstract The reinforcement of rubber compounds with short fibers has, at times, become necessary in many product applications. Particularly compounds with relatively low fiber content have proven successful in improving hose and belt performance. This is mostly due to an increase in composite stiffness without a great sacrifice of basic processability characteristics of the compound. Too large a fiber content becomes a primary source of difficulties during manufacture and/or product performance. Therefore, an understanding of how various composite properties depend upon fiber and matrix properties, as well as on fabrication methods, will help design better products. The mechanical properties, such as modulus, strength, and ultimate elongation depend upon fiber orientation, aspect ratio, and adhesion between fiber and matrix compound. Unfortunately, the degree and type of adhesion cannot be estimated quantitatively at present even though its importance in the improvement of composite properties is well recognized. Aspect ratio is another parameter which can be used in improving composite properties. As a rule, a higher aspect ratio gives higher composite stiffness. During processing, fibers are buckled and crimped under large deformations, which results in a distribution of fiber lengths, rather than a constant length as before mixing, as shown, for example, in Figure 1. One can, therefore, expect to achieve the same composite properties regardless of the initial fiber length (up to, say, 15 mm) or fiber length distribution. Of the three parameters, fiber orientation affects composite properties the most. During processing (milling, extrusion, etc.) of rubber composites, the fibers tend to orient along the flow direction, causing mechanical properties to vary in different directions. Therefore, by changing or suitably controlling the flow direction, optimum properties can be generated for a given product. A good example is the balanced fiber orientation in a hose which gives optimum design strength. Milling or calendering is perhaps the most commonly used processing method in which fibers tend to orient along the mill direction. Since each mill or calender differs from any other in size, roll speed, and other characteristics, it is essential to determine the influence of these parameters on composite properties. Results of a systematic study to identify significant mill parameters which influence the composite properties are presented here.

Effect of the initial fiber alignment on the mechanical properties for GMT composite materials

2017 ◽  
Vol 31 (1) ◽  
pp. 91-109 ◽  
Author(s):  
Yuyang Song ◽  
Umesh Gandhi ◽  
Adam Koziel ◽  
Srikar Vallury ◽  
Anthony Yang
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Fiber Length ◽  
Initial Conditions ◽  
Length Distribution ◽  
Material Model ◽  
Bending Test ◽  
Process Conditions ◽  
Fiber Concentration ◽  
Finished Part

A glass-mat-reinforced thermoplastic (GMT) material is widely used in the automotive industry for components such as underbody shields, seat structures, front/rear bumper, and front-end modulus. Due to the higher residual length of the glass strands, GMT usually offers better mechanical properties than injection-molded fiber-reinforced thermoplastics. The GMT material is typically manufactured by compression molding (CM) of preimpregnated fibers–reinforced resin sheets called mat. Two types of mats, one with discontinuous random (RD) fibers and other with aligned continuous fibers, are considered in this study. A stack of such mats with different combinations is used to tailor the mechanical properties of the final part. During the CM, the fibers in the mat flow with the resin and change the alignment. In this study, we are presenting an approach to account for the initial condition, such as fiber length, orientation and concentration of the fibers in the mat, and process conditions used, to develop a material model for the finished part. First, a stack of mat with known fiber orientation, length, and concentration as initial conditions is simulated for CM to predict the fiber orientation in the finished part. Next, the material model for the finished parts is developed using a Mori–Tanaka homogenization approach. The fiber orientation in the finished part is mapped from the CM simulation. For the fiber concentration and fiber length distribution, we used an empirical approach. The cross section of the finished part is investigated under optical microscope, and the fiber length and concentration are estimated based on the microstructure and initial stacking of mats. The predicted fiber orientation tensor is verified with orientations measured using computerized tomography (CT) scan on actual parts. The material model is verified by comparing the predicted performance with the actual tensile and bending test results.

scholarly journals RVE modelling of short fiber reinforced thermoplastics with discrete fiber orientation and fiber length distribution

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Kevin Breuer ◽  
Markus Stommel
Keyword(s):  
Fiber Orientation ◽  
Fiber Length ◽  
Matrix Material ◽  
Length Distribution ◽  
Computational Effort ◽  
Fiber Reinforced ◽  
Fiber Length Distribution ◽  
Reinforced Thermoplastics ◽  
Composite Properties ◽  
Fiber Reinforced Thermoplastics

AbstractThis study presents an analysis of modelling aspects on the effective composite properties of short glass fiber reinforced thermoplastics using representative volume elements (RVE). Although, many investigations were published showing effects of different modelling parameters of RVEs, we further elaborate in this contribution the parameters: influence of fiber packing, fiber shape, bonding of the fibers to the matrix, fiber length distribution and fiber orientation. The knowledge of these influences is used to determine the extent to which the increased modelling accuracy and thus the computational effort leads to an improved RVE’s forecast quality. This objective is achieved by creating and comparing different RVE models of a PBT-GF20 composite. The information required for the RVE models is obtained by experimental characterization of the PBT-GF20 and the PBT matrix material. It can be concluded based on the results of the numerical investigations in conjunction with the experimental tests of the composite that fiber packing, fiber length distribution, fiber orientation and fiber geometry are essential for a precise determination of the effective composite properties.

Experimental study on effect of fiber length and fiber content on tensile and flexural properties of bamboo fiber/epoxy composite

2019 ◽  
Vol 15 (5) ◽  
pp. 947-957 ◽  
Author(s):  
Giridharan R. ◽  
Raatan V.S. ◽  
Jenarthanan M.P.
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Epoxy Composite ◽  
Natural Fibers ◽  
Weight Ratio ◽  
Fiber Content ◽  
Bamboo Fiber ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Content Type

Purpose The purpose of this paper is to study the effects of fiber length and content on properties of E-glass and bamboo fiber reinforced epoxy resin matrices. Experiments are carried out as per ASTM standards to find the mechanical properties. Further, fractured surface of the specimen is subjected to morphological study. Design/methodology/approach Composite samples were prepared according to ASTM standards and were subjected to tensile and flexural loads. The fractured surfaces of the specimens were examined directly under scanning electron microscope. Findings From the experiment, it was found that the main factors that influence the properties of composite are fiber length and content. The optimum fiber length and weight ratio are 15 mm and 16 percent, respectively, for bamboo fiber/epoxy composite. Hence, the prediction of optimum fiber length and content becomes important, so that composite can be prepared with best mechanical properties. The investigation revealed the suitability of bamboo fiber as an effective reinforcement in epoxy matrix. Practical implications As bamboo fibers are biodegradable, recyclable, light weight and so on, their applications are numerous. They are widely used in automotive components, aerospace parts, sporting goods and building industry. With this scenario, the obtained result of bamboo fiber reinforced composites is not ignorable and could be of potential use, since it leads to harnessing of available natural fibers and their composites rather than synthetic fibers. Originality/value This work enlists the effect of fiber length and fiber content on tensile and flexural properties of bamboo fiber/epoxy composite, which has not been attempted so far.

scholarly journals Thermal and Mechanical properties of epoxy-jute fiber composite

2014 ◽  
Vol 27 (2) ◽  
pp. 77-82 ◽  
Author(s):  
H Ahmad ◽  
MA Islam ◽  
MF Uddin
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Fiber Length ◽  
Epoxy Composite ◽  
Fiber Composite ◽  
Young Modulus ◽  
Fiber Content ◽  
Jute Fiber ◽  
Elongation At Break

Chopped jute fiber-epoxy composites with varying fiber length (2-12 mm) and mass fraction (0.05-0.35) had been prepared by a heat press unit. The cross-linked product was characterized in terms of specific gravity, thermal conductivity, tensile strength, Young modulus and elongation at break. The transverse thermal conductivities for randomly oriented fibers in the composite were investigated by Lees and Charlton’s method. The tensile strength, Young modulus and elongation at break were investigated by a Universal Tensile Tester. With an increase in the fiber content (irrespective of the fiber length), the thermal conductivity of the composite decreases; the decreasing rate being highest for the fiber length of 2 mm followed by that for the fiber length of 6 and 12 mm. The decreasing rate of the thermal conductivity of the jute-epoxy composite is comparatively higher to that reported in literature for acrylic polymer hemp fiber composite. The tensile strength also decreases with the increase of the fiber content in the composite. The fiber length does not show to have significant effect on the tensile strength of the composite; the variation in strength being masked within experimental error. The Young modulus increases with the increase of fiber content within elastic limit; showing the highest values for the fiber length of 6 mm followed by those for the fiber length of 2 mm and 12 mm. The elongation at break shows slightly increasing trend up to 15% fiber content, but beyond that it decreases drastically. The specific gravity decreases with the increase in the fiber content and thus the recalculated specific tensile strength is found to keep at a stable level of 36MPa up to the fiber content of 20%, and beyond that the specific tensile strength decreases with the increase in the fiber content. It is concluded that jute fiber-epoxy composite could be used as a good heat-insulating material. Further investigation is recommended on the improvement of the thermal insulation keeping the mechanical properties unchanged or even improved. The TGA study is also required to ascertain the field of application of the material. DOI: http://dx.doi.org/10.3329/jce.v27i2.17807 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 2, December 2012: 77-82

Preparing of SMC Artificial Marble and its Mechanical Properties

2011 ◽  
Vol 55-57 ◽  
pp. 447-450 ◽  
Author(s):  
Jian Li ◽  
Zheng Qun Huang ◽  
Yan Qin
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Fiber Length ◽  
Filler Content ◽  
Fiber Content ◽  
Molding Temperature ◽  
Overall Performance ◽  
The Impact

In this article, a kind of SMC artificial marble was prepared. In order to enhance the mechanical properties and prolong the using life of SMC artificial marble, some effects such as fiber content, filler content and molding temperature etc. on the mechanical properties were carefully studied, too. Results showed that the increase of fiber content could improve the impact strength of SMC artificial marble when the fiber length was 10mm and the increase of filler content would decrease the flexural strength of SMC artificial marble. And the molding temperature at the range of 130°C ~ 160°C had little influence on the mechanical properties of SMC artificial marble. Comparing with natural marble and casting marble, SMC artificial marble owed superior overall performance and it was much more suitable for industry production.

Study on Ramie Fiber Reinforced Polypropylene Composites (RF-PP) and its Mechanical Properties

2008 ◽  
Vol 41-42 ◽  
pp. 313-316 ◽  
Author(s):  
Li Ping He ◽  
Yong Tian ◽  
Lu Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Fiber Content ◽  
Ramie Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Environmental Friendly ◽  
Pp Composites ◽  
Pre Treatment ◽  
The Impact

Natural fiber reinforced polypropylene composites (NF/PP) have attracted a lot of attention because of their light weight, good mechanical properties, recyclable and environmental friendly features. This work has successfully fabricated ramie fiber reinforced polypropylene composites (RF/PP) with a hybrid method of melt-blending and injection molding. Different RF/PP eco-materials have been fabricated by varying the fiber length, fiber content and way of fiber pre-treatment. This paper studied the mechanical properties of the fabricated RF/PP composites in depth by investigating the mechanical behaviors of RF/PP and microstructures of the ruptured surfaces. The results show that the increases of fiber length and fiber content can improve the tensile strength, flexural strength and compression strength apparently, but result in negative influences on the impact strength and elongation behaviors of RF/PP composites. The optimal addition amount of ramie fiber is around 20 wt%. The pre-treatment of ramie fiber in 10%~15% NaOH is good to the mechanical properties of RF/PP. The fiber length can be varied in the range of 3-8 mm. It is expected that the fabricated RF/PP composites can be applied to automobile industry as environmental friendly eco-materials.

Composite Soil: Fiber Inclusion and Strength

2011 ◽  
Vol 308-310 ◽  
pp. 1646-1650 ◽  
Author(s):  
Amin Chegenizadeh ◽  
Hamid Nikraz
Keyword(s):  
Aspect Ratio ◽  
Fiber Length ◽  
Civil Engineering ◽  
Geotechnical Engineering ◽  
Reinforced Soil ◽  
Fiber Content ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Pavement Engineering ◽  
Grade Material

Reinforced soil has been among the most effective soil modification materials. Its use has been expanded rapidly into civil engineering, geotechnical engineering and pavement engineering. Reinforcing subgarde in pavement systems has always been an issue. This study focuses on effect of fiber inclusion on the strength of subgrade material. Plastic fiber was used for this investigation. Fiber contents and aspect ratio have been changed during these tests. The fiber percentage varied from 0 % (for unreinforced samples) to 2%. Clay was used as sub grade material. Unconfined compression tests were carried out to investigate behaviour of the composite under different condition. The fiber length and fiber content found to play important rule on the strength of composite. Furthermore it was observed that ductility of sample increased by fiber inclusion.

Effect of Doffer Speed on Fiber Length Distribution in Flat Strips

2014 ◽  
Vol 1048 ◽  
pp. 89-93
Author(s):  
Xin Guo ◽  
Lan Jie Xu ◽  
Peng Zi Sun
Keyword(s):  
Fiber Length ◽  
Length Distribution ◽  
Short Fiber ◽  
Fiber Content ◽  
Test Results ◽  
Fiber Length Distribution ◽  
Better Than

The effect of doffer speed on fiber length distribution in flat strips was studied. The fiber length of flat strips produced at three doffer speeds was tested by Premier aQura neps and short fiber tester. The test results show that 1fiber length in flat strips is between 6-38 mm; 2doffer speed has some effect on flat strips quality, which is best at the doffer speed of 20r/min; 3 3% ,5% fiber length and effective fiber length at the doffer speed of 25r/min are better than those at the doffer speed of 30r/min, but short fiber content (<12.7mm and <16 mm ) at the doffer speed of 25r/min are less than those at the doffer speed of 30r/min 4 from the viewpoint of fiber length distribution, the doffer speed of 30r/min is better than that of 25r/min; 5it may not be complete only using fiber length parameters to judge the carding effect, and the fiber length distribution may be more accurate to evaluate the carding process.

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