Short Fiber Reinforced Composite: The Effect of Fiber Length and Volume Fraction

2006 ◽  
Vol 7 (5) ◽  
pp. 10-17 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan K. Garoushi
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Volume Fraction ◽  
Testing Machine ◽  
Short Fiber ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Abstract Aim The aim of this study was to determine the effect of short fiber volume fraction and fiber length on some mechanical properties of short fiber-reinforced composite (FRC). Methods and Materials Test specimens (2 x 2 x 25 mm3) and (9.5 x 5.5 x 3 mm3) were made from short random FRC and prepared with different fiber volumes (0%-22%) and fiber lengths (1-6 mm). Control specimens did not contain fiber reinforcement. The test specimens (n=6) were either dry stored or thermocycled in water (x10.000, 5 – 55°C) before loading (three-point bending test) according to ISO 10477 or statically loaded with a steel ball (Ø 3.0 mm) with a speed of 1.0 mm/min until fracture. A universal testing machine was used to determine the flexural properties and the load-bearing capacity. Data were analyzed using analysis of variance (ANOVA) (p=0.05) and a linear regression model. Results The highest flexural strength and fracture load values were registered for specimens with 22 vol% of fibers (330 MPa and 2308 N) and with 5 mm fiber length (281 MPa and 2222 N) in dry conditions. Mechanical properties of all test specimens decreased after thermocycling. ANOVA analysis revealed all factors were affected significantly on the mechanical properties (p<0.001). Conclusions By increasing the volume fraction and length of short fibers up to 5 mm, which was the optimum length, the mechanical properties of short FRC were improved. Citation Garoushi SK, Lassila LVJ, Vallittu PK. Short Fiber Reinforced Composite: The Effect of Fiber Length and Volume Fraction. J Contemp Dent Pract 2006 November;(7)5:010-017.

Robotic Manufacturing of Near-Net Shaped Short-Fiber Reinforced Composites With Functional Properties

2009 ◽  
Author(s):  
Antony Paul ◽  
Jeffery M. Gallagher ◽  
Raymond J. Cipra ◽  
Thomas Siegmund
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Fiber Composite ◽  
Imaging Techniques ◽  
Short Fiber ◽  
Robotic Arm ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Geometric Data ◽  
Reinforced Composite

Fiber reinforced composite materials are now frequently being used over conventional materials for their ability to achieve tailored properties and performance characteristics. With the recent advancements in manufacturing techniques, short-fiber composites are coming into prominence in this sector, with their cost advantage and their capability for large throughput. Randomness of fiber orientation is inherent to short fiber composite manufacturing processes. In order to effectively manipulate the mechanical properties of a short-fiber reinforced composite, it is imperative to adequately control the orientation of the fibers during the deposition stage. A process is currently developed to acquire geometrical data of the target object and to utilize it to create a short-fiber reinforced component with controlled fiber orientation. The topological data acquisition of the object is made possible using non-contact 3D imaging techniques. The geometric data is then transferred to a commercial CAD package for the added capability to manipulate the geometry as may be required for specific applications. Subsequently, geometric data constitutes the basis of path planning for the tooling processes. In our process, a novel rapidly re-configurable tooling and molding technology is employed by which a 6-axis robotic arm is used to sculpt a pin-device vacuum surface. After the tooling is completed, the robotic arm will use a deposition nozzle to orient a steady stream of initially random short-fiber from a feeder into a unidirectional output, onto the tool surface. By controlling the position and orientation of the deposition nozzle, it is possible to control the orientation and density of fiber in each section of the near-net shaped composite pre-form. The fiber pre-form is then impregnated with a suitable matrix medium and cured to create the required component. The outlined process is thus capable of manufacturing a near-net shaped short-fiber reinforced component with highly specific mechanical properties. One of the many applications envisaged using this process is the manufacture of custom form-fitting braces, masks and guards for use in healthcare products. A patient intervention can have his or her features acquired using stereo-imaging and have corrective measures incorporated into the device prior to manufacturing. By controlling the orientation and density of the fiber at different portions of the device, it is possible to provide adequate support at specific areas or to restrict movement in specific directions while providing compliance to movement in the others.

Fiber-Matrix Interfacial Area Reduction in Fiber Reinforced Cements and Concretes at Moderate to High Fiber Volume Fractions

1994 ◽  
Vol 370 ◽  
Author(s):  
Gebran N. Karam
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Interfacial Area ◽  
Composite Fiber ◽  
Short Fiber ◽  
Published Data ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
High Fiber ◽  
Fiber Matrix

AbstractThe area and properties of the fiber-matrix interface in fiber reinforced cements and concretes determines the amount of stress transferred forth and back between the cement paste and the reinforcement and hence controls the mechanical properties of the composite. Fiber-fiber interaction and overlap of fibers with fibers, voids and aggregates can dramatically decrease the efficiency of the reinforcement by reducing this interfacial area. A simple model to account for this reduction is proposed and ways to integrate it in the models describing the mechanical properties of short fiber reinforced concretes are presented. The parameters of the model are evaluated from previously published data sets and its predictions are found to compare well with experimental observations; for example, it is able to predict the non-linear variation of bending and tensile strength with increasing fiber volume fraction as well as the existence of an optimal fiber content.

Evaluation of Shear Bond Strength of Fiber-reinforced Composite and Methacrylate-based Composite to Pure Tricalcium-based Cement

2016 ◽  
Vol 8 (1) ◽  
pp. 25-27
Author(s):  
Ravula A Reddy ◽  
RS Basavanna
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
High Stress ◽  
Short Fiber ◽  
Strength Analysis ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Group I

ABSTRACT Aim Fracture of restorative composite is reported as a common reason for replacement. Due to failures of this kind, it is still controversial whether restorative composites should be used in large, high-stress-bearing applications, such as in direct posterior restorations. The high brittleness of current composites hinders their use in large stress-bearing areas. Thus, recently short fiber-reinforced composite was introduced as dental restorative composite resin. The aim of the article is to evaluate shear bond strength of fiber-reinforced composite (everX Posterior) and methacrylate-based composite (FILTEK Z250) to pure tricalcium silicate-based cement (biodentine). Materials and methods Acrylic blocks (n = 30) with 2 mm high and 5 mm diameter central holes were prepared. The samples were taken and filled with biodentine and were divided into two groups containing 15 in each group. Group I: Fiber-reinforced composite. Group II: Methacrylate-based composite, which are layered over biodentine. The specimens are transferred to the universal testing machine and subjected to shear bond strength analysis at a cross-head speed of 1.0 mm/minute. Results The bond strength values were significantly higher in case of fiber-reinforced composite when compared with methacrylate-based composite. Conclusion Within the limitations of the study, it was concluded that the fiber-reinforced composite with biodentine had highest bond strength when compared with methacrylate-based composite. Clinical significance Fiber-reinforced composite has excellent fatigue resistance because the embedded fibers are bonded to the polymer matrix and allow the stresses to be distributed effectively throughout the restoration. They are most suitable for applications in which the direction of highest stress is predictable. They are used in cavities with three or more surfaces missing and also in large-sized cavities. They are extensively used in cavities where inlays and onlays are prescribed. How to cite this article Reddy RA, Basavanna RS. Evaluation of Shear Bond Strength of Fiber-reinforced Composite and Methacrylate-based Composite to Pure Tricalcium-based Cement. CODS J Dent 2016;8(1):25-27.

scholarly journals Effect of Plasma and Fiber Position on Flexural Properties of a Polyethylene Fiber-Reinforced Composite

2015 ◽  
Vol 26 (5) ◽  
pp. 490-496 ◽  
Author(s):  
Silvana M. M. Spyrides ◽  
Maíra do Prado ◽  
Renata Antoun Simão ◽  
Fernando Luis Bastian
Keyword(s):  
Plasma Treatment ◽  
Testing Machine ◽  
Bending Test ◽  
Flexural Properties ◽  
Control Group ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Polyethylene Fiber ◽  
Fiber Position

Abstract: The aim of this study was to evaluate the effect of plasma treatment using argon and oxygen gases, combined with fiber position on flexural properties of a fiber-reinforced composite. Eleven groups were evaluated, a non-reinforced control group and 10 groups reinforced with InFibra, a woven polyethylene fiber, varying according to the plasma treatment and fiber position. The samples were prepared using a stainless steel two-piece matrix. The three point bending test was performed in an EMIC testing machine. Flexural strength (FS) and flexural deflection (FD) were calculated from initial (IF) and final (FF) failure. Data were evaluated statistically using Kruskal-Wallis and Mann-Whitney tests (p<0.05). For IF, in all groups with fibers placed on the base, the FS and FD values were significantly higher than those positioned away from the base. The highest value of FS was obtained in the group treated with O 3 min (296.2 MPa) and the highest value of FD was obtained in the group treated with 1 min (0.109 mm). For FF the FS and FD values obtained for the groups with fibers positioned away from the base were similar or higher than those placed on the base. The highest FS value was obtained in the group treated with 1 min (317.5 MPa) and the highest FD value was obtained in the group treated with O 3 min (0.177 mm). Plasma treatment influenced FS and FD. Fiber position and plasma treatment affected the flexural properties of a fiber-reinforced composite.

scholarly journals Effect of Glass Fiber Length on Flexural Strength of Fiber-reinforced Composite Resin

2012 ◽  
Vol 3 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Tavakkol Omid ◽  
Mortazavi Moghaddam Venus ◽  
Sharafeddin Farahnaz ◽  
Alavi Ali Asghar
Keyword(s):  
Flexural Strength ◽  
Glass Fiber ◽  
Fiber Length ◽  
Composite Resin ◽  
Testing Machine ◽  
Fracture Load ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Post Hoc

ABSTRACT The aim of this study was to determine experimentally maximum fracture load of fiber-reinforced composite with different span lengths and to determine the effect of glass fiber on this parameter. Materials and methods Six fiber-reinforced groups (n = 10) were made with three different lengths (10, 15, 20 mm) with or without glass fiber in split mold. The specimens were early cured and then post-cured with a labolite unit, then specimens were subjected to three-point flexural test by a universal testing machine. Data were analyzed with ANOVA and LSD post-hoc test (p < 0.05). Results Maximum fracture load of specimens increased with decreasing lengths (p < 0.001) and fiber-containing group showed significantly higher fracture load than fiberless groups (p < 0.001). Conclusion It was concluded that by increasing the span length, the maximum fracture load values (N) decreased incorporation of fiber results in higher fracture strength values. How to cite this article Omid T, Venus MM, Farahnaz S, Asghar AA. Effect of Glass Fiber Length on Flexural Strength of Fiber-reinforced Composite Resin. World J Dent 2012;3(2):131-135.

Application of Embedded Element in the Short Fiber Reinforced Composite

2018 ◽  
Vol 774 ◽  
pp. 241-246
Author(s):  
Jian Hong Gao ◽  
Xiao Xiang Yang ◽  
Li Hong Huang
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Aspect Ratio ◽  
Volume Fraction ◽  
Element Model ◽  
Short Fiber ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Edge Size

The finite element analysis (FEA) is a numerical method for predicting the mechanical property of short fiber reinforced composite usefully. However, as we know, there is always a “jamming” limit when generating fiber architecture expecially in the cases of high volume fraction and high aspect ratio of short fiber. Even if the volume fraction and aspect ratio in finite element model meet the practical requirements, the problem of mesh deformity will always occur which would lead to unconverge of numerical computation. In this work, embedded element technique which will help to reduce the probability of the above two problems is employed to establish the finite element model of short fiber reinforced composite. The effect of edge size, thickness and mesh density of FE models on the elastic modulus were investigated. Numerical results show that the value of elastic modulus mainly depend on the edge size and fiber amount of FE model while the effect of thickness can be neglected. The elastic modulus takes to converge for high element number. An inverse method is proposed to calculate volume fraction of short fibers, by which numerical results agree well with the calculation results of empirical formula based on Halpin-Tsai equation.

On Stiffness and Strength of an Aligned Short-Fiber Reinforced Composite Containing Fiber-End Cracks Under Uniaxial Applied Stress

1981 ◽  
Vol 48 (2) ◽  
pp. 361-367 ◽  
Author(s):  
M. Taya ◽  
T. Mura
Keyword(s):  
Applied Stress ◽  
Volume Fraction ◽  
Short Fiber ◽  
Fiber Axis ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Equivalent Inclusion Method ◽  
Reinforced Composite ◽  
Penny Shaped Crack ◽  
Shaped Crack

One of the experimental findings on short-fiber reinforced composite materials is that the fiber-ends act as a crack initiator. The effect of the fiber-end crack on the overall stiffness and the strength of the composite are investigated here. A particular emphasis is placed upon the weakening longitudinal Young’s modulus by the fiber-end crack which is assumed to be penny-shaped. The energy release rate of the penny-shaped crack at the fiber-end under a uniaxial applied stress is also calculated for a fracture criterion. It is assumed in our theoretical model that short-fibers are all aligned in the loading direction and the penny-shaped crack at the fiber-end extends in the direction perpendicular to the fiber axis. Our analytical technique is a combination of Eshelby’s equivalent inclusion method and Mori-Tanaka’s back stress analysis so that our results are valid even for large volume fraction of fibers.

Sign in / Sign up

Export Citation Format

Share Document