Development of Generalized Plane-Strain Tensors for the Concentric Cylinder

1995 ◽  
Vol 62 (3) ◽  
pp. 590-594
Author(s):  
N. Chandra ◽  
Zhiyum Xie
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Transformation Strain ◽  
Inclusion Problem ◽  
Infinite Domain ◽  
Concentric Cylinder ◽  
Finite Radius ◽  
Fiber Volume ◽  
Thermal Residual Stresses ◽  
The Matrix

A pair of two new tensors called GPS tensors S and D is proposed for the concentric cylindrical inclusion problem. GPS tensor S relates the strain in the inclusion constrained by the matrix of finite radius to the uniform transformation strain (eigenstrain), whereas tensor D relates the strain in the matrix to the same eigenstrain. When the cylindrical matrix is of infinite radius, tensor S reduces to the appropriate Eshelby’s tensor. Explicit expressions to evaluate thermal residual stresses σr, σθ and σz in the matrix and the fiber using tensor D and tensor S, respectively, are developed. Since the geometry of the present problem is of finite radius, the effect of fiber volume fraction on the stress distribution can be easily studied. Results for the thermal residual stress distributions are compared with Eshelby’s infinite domain solution and finite element results for a specified fiber volume fraction.

Determination of fiber volume fraction in a cured laminate

2021 ◽  
pp. 002199832110112
Author(s):  
Qing Yang Steve Wu ◽  
Nan Zhang ◽  
Weng Heng Liew ◽  
Vincent Lim ◽  
Xiping Ni ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Evaluation Method ◽  
Volume Fraction ◽  
Matrix Material ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
Fiber Volume ◽  
Laser Ultrasonic ◽  
The Matrix

Propagation of ultrasonic wave in Carbon Fiber Reinforced Polymer (CFRP) is greatly influenced by the material’s matrix, resins and fiber volume ratio. Laser ultrasonic broadband spectral technique has been demonstrated for porosity and fiber volume ratio extraction on unidirection aligned CFRP laminates. Porosity in the matrix materials can be calculated by longitudinal wave attenuation and accurate fiber volume ratio can be derived by combined velocity through the high strength carbon fiber and the matrix material with further consideration of porosity effects. The results have been benchmarked by pulse-echo ultrasonic tests, gas pycnometer and thermal gravimetric analysis (TGA). The potentials and advantages of the laser ultrasonic technique as a non-destructive evaluation method for CFRP carbon fiber volume fraction evaluation were demonstrated.

The Influence of Alloy Chemistry on Controlling Fiber Volume Fraction in Ni-Base Mc Aligned Eutectics

1981 ◽  
Vol 12 ◽  
Author(s):  
M. R. Jackson ◽  
J. L. Walter
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Major Influence ◽  
Ideal Solution ◽  
Fiber Volume ◽  
Strong Function ◽  
Alloy Chemistry ◽  
Ideal Solution Behavior ◽  
Small Influence ◽  
The Matrix

ABSTRACTFor the Ni-base TaC eutectics, it has been shown previously that carbide volume fraction is a strong function of Ta/C ratio. Now in a number of Ni,Cr-TaC and Ni,Cr,Al-TaC alloys, Cr has been observed to have only a small influence on volume fraction of carbide, while Al has a major influence acting to decrease the volume fraction. The Al present in the matrix causes the phase equilibrium to approach that of a much greater Ta/C ratio. This analysis has been extended to more complex NiTaC alloys as well. For the simple Ni-Cr-Ta-C alloys, creep behavior has been studied as a function of volume fraction of carbide.Other carbide systems have been evaluated as well, including TiC and NbC. A general understanding of volume fraction differences between these systems and TaC can be reached by consideration of ideal solution behavior and the appropriate phase diagrams.

Effect of Fiber Volume Fraction on High Temperature Creep of Al2O3-SiO2(sf)/AZ91D Composite

2011 ◽  
Vol 474-476 ◽  
pp. 548-552
Author(s):  
Jun Tian
Keyword(s):  
Creep Resistance ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Matrix Alloy ◽  
Short Fiber ◽  
Tensile Creep ◽  
Short Fibers ◽  
Creep Tests ◽  
Fiber Volume ◽  
The Matrix

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.

Experimental Investigation of Interface Properties in SiC Fiberreinforced Reaction-Bonded Silicon Nitride Matrix Composites

1994 ◽  
Vol 365 ◽  
Author(s):  
J.I. Eldridge ◽  
R.T. Bhatt
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Interfacial Properties ◽  
Interface Properties ◽  
Matrix Composites ◽  
Fiber Volume ◽  
The Matrix ◽  
Push Out ◽  
Spacing Method

ABSTRACTInterfacial properties of 1-D SiC/RBSN composites were measured by the matrix crack spacing method and by the fiber push-out method, and the results were compared. The composites consisted of 8 to 33 vol% of aligned SCS-6 SiC fibers (142 μm diameter) in a relatively porous (20 to 40 vol%) Si3N4 matrix. The effects of fiber volume fraction and test temperature on the interfacial properties have been investigated. The advantages and limitations of both methods in evaluating the interface properties of fiber-reinforced ceramic matrix composites and the factors influencing the interfacial measurements are discussed.

Development of beneficial residual stresses in glass fiber epoxy composites through fiber prestressing

2020 ◽  
Vol 39 (13-14) ◽  
pp. 487-498
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Residual Stresses ◽  
Tensile Testing ◽  
Compressive Residual Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
New Approach ◽  
The Matrix

The undesired residual stresses in fiber reinforced polymer composites are developed during their manufacturing processes due to the thermal and chemical shrinkage of the polymer matrix, which negatively affect the performance of the composites. Applying tensile stress to the reinforcement fibers during the curing of the matrix can reduce or eliminate the undesired residual stresses. Furthermore, the undesired tensile residual stress within the matrix can be replaced with beneficial compressive residual stress which can improve the mechanical properties of the composites. In this study, theoretical stress analysis was performed in order to determine the value of the optimum compressive residual stress that is associated with the highest tensile strength. This value was determined based on the tensile testing result of prestressed composites with a 40% fiber volume fraction. For the composites with different fiber volume fractions, a new approach was introduced to estimate the optimum fiber prestressing level which generates the optimum compressive residual stress within the matrix and consequently, the highest tensile strength can be achieved. In order to validate this approach experimentally, prestressed composites with 25 and 30% fiber volume fraction were prepared by applying the estimated optimum fiber prestressing levels during curing of matrix and tensile testing was performed. The result of the stress analysis showed that the value of the optimum compressive residual stress corresponding to the highest tensile strength is 2.5 MPa approximately. The tensile testing results confirmed the validity of the new approach in estimating the optimum fiber prestressing level for the composites with different fiber volume fractions. For both prestressed composites with 25 and 30% fiber volume fraction, the highest tensile strength was achieved when the theoretically estimated optimum fiber prestressing level was applied to the fibers during the curing of the matrix.

Effect of the Carbon Nanotube Distribution on the Thermal Conductivity of Composite Materials

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Iman Eslami Afrooz ◽  
Andreas Öchsner
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Finite Element Analysis ◽  
Composite Materials ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Element Analysis ◽  
The Matrix ◽  
Good Agreement

Finite element analysis has been employed to investigate the effect of carbon nanotubes (CNTs) distribution on the thermal conductivity of composite materials. Several kinds of representative volume elements (RVEs) employed in this study are made by assuming that unidirectional CNTs are randomly distributed in a polymer matrix. It is also assumed that each set of RVEs contains a constant fiber volume fraction and aspect ratio. Results show that randomness—the way in which fibers are distributed inside the matrix—has a significant effect on the thermal conductivity of CNT composites. Results of this study were compared using the analytical Xue and Nan model and good agreement was observed.

Friction and Wear Properties of Carbon Fiber Reinforced Polypropylene Composites

2011 ◽  
Vol 284-286 ◽  
pp. 2380-2383 ◽  
Author(s):  
Jian Li ◽  
Chi Lan Cai
Keyword(s):  
Friction And Wear ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Wear Properties ◽  
Fiber Volume ◽  
Rotating Speed ◽  
Polypropylene Composites ◽  
Linear Evolution ◽  
The Matrix ◽  
Friction And Wear Properties

The friction and wear properties of carbon fibers (CF) reinforced polypropylene (PP) composite were studied. The influences of the fiber volume fraction, load applied, rotating speed, and wear mechanism were discussed. The results indicated that CF/PP composite had better tribological properties than pure PP. The friction coefficient and wear mass loss decreased with the fiber volume fraction increased, but increased as the load and rotating speed increased, respectively. CF reduced direct contact between the matrix and counterpart and improved the wear resistance of CF/PP composite greatly. The wear displayed a linear evolution in all the range of load. Surfaces after wear tests were characterized using scanning electron microscopy (SEM).

Vehicle Body of Ganesha Underwater Scooter: Toughness Characteristics of Polyester Matrix Composite Hybrid Reviewed from Variation of Rami Fiber Volume Fraction

2019 ◽  
Vol 291 ◽  
pp. 91-97
Author(s):  
Rihendra Dantes Kadek
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fracture Pattern ◽  
Vehicle Body ◽  
Fiber Volume ◽  
Hemp Fiber ◽  
The Matrix ◽  
Polyester Matrix ◽  
Independent Variable ◽  
Composite Toughness

This study aimed to determine the influence of fiber volume fraction towards composite toughness and the composite hybrid fracture pattern models reinforced by hemp fiber and fiberglass to find out the ratio of composite toughness from variation of hemp fiber volume fraction and fiberglass A1 (15 : 25), A2 (20 : 20), A3 (25 : 15)%. This research is an experimental method research with the dependent variable is composite toughness and the independent variable is the fiber volume fraction. Based on the test and data analysis, the results for fraction A1 (15 : 25)% have the greatest impact absorption of 10834.6 J/m2 compared to A2 (20 :20)% that have absorption of 8470.828 J/m2 and A3 (25 : 15)% is 7168.813 J/m2. The most prominent one of the three variations of volume fractions on this fracture pattern analysis is the existence of (delamination) or there are fibers which are not perfectly exposed to the matrix. The Delamination usually occurs due to overly tightening of the fibers.

ANALISIS SIFAT MEKANIK KOMPOSIT LAMINA BERPENGUAT SERAT KACA WOVEN DENGAN MATRIKS UNSATURATED POLYESTER 2504 APT

ROTOR ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Naafi' Ul Amri ◽  
Gaguk Jatisukamto ◽  
Sumarji Sumarji
Keyword(s):  
Flexural Strength ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Unsaturated Polyester ◽  
Glass Fibers ◽  
Fiber Volume ◽  
Axis Direction ◽  
Matrix Volume ◽  
The Matrix ◽  
The Difference

Polymer composites has anisotropic properties, if it receives stress from outside it will increase deformation in all directions. This study aims to determine the effect of composites lamina made from woven glass fibers on 2504 APT unsaturated polyester on tensile and flexural strength. The research methodology used is as follows: the process of making composites using the Hand-Lay Up method, the matrix volume fraction Vfm = 69, 39%, the fiber volume fraction Vfs = 30, 38%. The research parameters observed are the x-direction stress (sx) and the y-axis direction strees, (sy). The results obtained are the y-axis, (sy) = 0.8% greater than the x-axis. The flexural strength of the x-axis direction, (sbx) = 57,7% greater than the y-axis direction. The difference in the value of the tensile strength occurs in the number of different fiber bonds, while the flexural strength of the y direction occurs in the fiber lamina which increases more.

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