Effective Electromechanical Properties of 622 Piezoelectric Medium With Unidirectional Cylindrical Holes

2013 ◽  
Vol 80 (5) ◽  
Author(s):  
Adair Roberto Aguiar ◽  
Julián Bravo Castillero ◽  
Reinaldo Rodríguez Ramos ◽  
Uziel Paulo da Silva
Keyword(s):  
Volume Fraction ◽  
Effective Properties ◽  
Matrix Material ◽  
Piezoelectric Medium ◽  
Composite State ◽  
Periodic Distribution ◽  
Infinite Systems ◽  
Linear Algebraic Equations ◽  
The Matrix ◽  
Cylindrical Holes

The asymptotic homogenization method (AHM) yields a two-scale procedure to obtain the effective properties of a composite material containing a periodic distribution of unidirectional circular cylindrical holes in a linear transversely isotropic piezoelectric matrix. The matrix material belongs to the symmetry crystal class 622. The holes are centered in a periodic array of cells of square cross sections and the periodicity is the same in two perpendicular directions. The composite state is antiplane shear piezoelectric, that is, a coupled state of out-of-plane shear deformation and in-plane electric field. Local problems that arise from the two-scale analysis using the AHM are solved by means of a complex variable method. For this, the solutions are expanded in power series of Weierstrass elliptic functions, which contain coefficients that are determined from the solutions of infinite systems of linear algebraic equations. Truncating the infinite systems up to a finite, but otherwise arbitrary, order of approximation, we obtain analytical formulas for effective elastic, piezoelectric, and dielectric properties, which depend on both the volume fraction of the holes and an electromechanical coupling factor of the matrix. Numerical results obtained from these formulas are compared with results obtained by the Mori–Tanaka approach. The results could be useful in bone mechanics.

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.

scholarly journals Functional Application for the Corn Leaf Fibre to Make Reinforced Polymer Composites Sheet

2021 ◽  
Author(s):  
Ramratan Guru ◽  
Anupam Kumar ◽  
Rohit Kumar
Keyword(s):  
Volume Fraction ◽  
Agricultural Waste ◽  
Matrix Material ◽  
Research Work ◽  
Weight Fraction ◽  
Natural Fibre ◽  
Raw Material ◽  
Corn Husk ◽  
The Matrix ◽  
Composite Product

This research work has mainly utilized agricultural waste material to make a good-quality composite sheet product of the profitable, pollution free, economical better for farmer and industries. In this study, from corn leaf fibre to reinforced epoxy composite product has been utilized with minimum 35 to maximum range 55% but according to earlier studies, pulp composite material was used in minimum 10 to maximum 27%. Natural fibre-based composites are under intensive study due to their light weight, eco-friendly nature and unique properties. Due to the continuous supply, easy of handling, safety and biodegradability, natural fibre is considered as better alternative in replacing many structural and non-structural components. Corn leaf fibre pulp can be new source of raw material to the industries and can be potential replacement for the expensive and non-renewable synthetic fibre. Corn leaf fibre as the filler material and epoxy as the matrix material were used by changing reinforcement weight fraction. Composites were prepared using hand lay-up techniques by maintaining constant fibre and matrix volume fraction. The sample of the composites thus fabricated was subjected to tensile, impact test for finding the effect of corn husk in different concentrations.

scholarly journals Extraction of void fraction in metal matrix composite using morphological image processing

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300
Author(s):  
Lun X. He ◽  
David K. Hsu ◽  
John P. Basart
Keyword(s):  
Image Processing ◽  
Void Fraction ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Matrix Material ◽  
Void Content ◽  
Matrix Composites ◽  
Cross Sectional ◽  
Morphological Image Processing ◽  
The Matrix

In continuous fiber reinforced metal matrix composites, the volume fraction of voids in the matrix material is an important parameter for material property characterization. In analyzing a cross-sectional micrograph of such a composite, the presence of fiber images and voids occurring on the perimeter of fibers complicates the determination of void content. This paper describes image processing steps using mathematical morphology for the extraction of void fraction in a composite.

Effect of Property of Interphase Layer on Damping Properties of Polymer Composites Using Sensitivity Analysis

2019 ◽  
Author(s):  
Shank S. Kulkarni ◽  
Alireza Tabarraei ◽  
Pratik Ghag
Keyword(s):  
Sensitivity Analysis ◽  
Attenuation Coefficient ◽  
Wave Attenuation ◽  
Volume Fraction ◽  
Matrix Material ◽  
Interphase Layer ◽  
Damping Properties ◽  
Damping Property ◽  
Interphase Region ◽  
The Matrix

Abstract This work studies the damping property of Nanocomposites through simulating wave propagation using the Finite Element Method (FEM). For this purpose Representative Volume Element (RVE) of the composite material is created using Random Sequential Absorption (RSA) algorithm. Damping property is represented using the wave attenuation coefficient. The matrix material is assumed to be isotropic visco-elastic in nature with randomly dispersed stiff elastic spherical fillers. In order to model mechanical imperfections at the boundary of fillers and matrix, the interphase layer is modeled surrounding the spherical fillers. Determining the thickness and stiffness of this interphase region is a challenging task. Therefore this study aims at investigating the effect of variation in thickness and stiffness values of the interphase region on damping property of whole composite using sensitivity analysis. Two specific cases with a volume fraction of 5 % and 8.6 % are selected for sensitivity analysis. It has been found that both the thickness and stiffness of the interphase region plays an important role in deciding the damping properties of the polymer composite. Value of attenuation coefficient is more sensitive to the thickness of interphase than stiffness and hence it is important to choose the value of thickness correctly for accurate predictions.

scholarly journals Finite Element Simulation of the Thermo-mechanical Response of Graphene Reinforced Nanocomposites

2018 ◽  
Vol 188 ◽  
pp. 01016
Author(s):  
Androniki S. Tsiamaki ◽  
Nick K. Anifantis
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Matrix Material ◽  
Continuum Theory ◽  
Element Model ◽  
Multilayer Graphene ◽  
Temperature Changes ◽  
The Matrix

The research for new materials that can withstand extreme temperatures and present good mechanical behavior is of great importance. The interest is highly focused on the utilization of composites reinforced by nanomaterials. To cope with this goal the present work studies the mechanical response of graphene reinforced nanocomposite structures subjected to temperature changes. A computational finite element model has been developed that accounts for both the reinforcement and the matrix material phases. The model developed is based on both the continuum theory and the molecular mechanics theory, for the simulation of the three different material phases of the composite, respectively, i.e. the matrix, the intermediate transition phase and the reinforcement. Considering this model, the mechanical response of an appropriate representative volume element of the nanocomposite is simulated under various temperature changes. The study involves different types of reinforcement composed from either monolayer or multilayer graphene sheets. Apart from the investigation of the behavior of a nanocomposite with each particular type of the reinforcement, comparisons are also presented between them in order to reveal optimized material combinations. The principal parameters taken into consideration, which contribute also to the mechanical behavior of the nanocomposite, are its size, the sheet multiplicity as well as the volume fraction.

Cavitation Erosion of Cobalt Alloy Coatings Containing Tungsten Carbide Particles in Hydrochloric and Sulphuric Corrosive Media

1993 ◽  
Vol 115 (2) ◽  
pp. 285-288 ◽  
Author(s):  
Wei Jun ◽  
Wang Fu-Xing ◽  
Cheng Yin-Qian ◽  
Chen Nan-Ping
Keyword(s):  
Tungsten Carbide ◽  
Cavitation Erosion ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Matrix Material ◽  
Cobalt Alloy ◽  
Corrosive Media ◽  
The Matrix ◽  
Cavitation Erosion Resistance ◽  
Carbide Particles

Cavitation erosion tests of composite coatings based on vacuum fusion sintered cobalt alloy containing tungsten carbide particles were carried out in 30 percent HCl and 50 percent H2SO4 solutions. The technique used included an ultrasonic vibratory apparatus at 30°C, 25μm amplitude and 30 kHz frequency. Weight loss was measured with an analytical balance and the microstructure was observed with SEM. The test results showed that the cavitation erosion resistance of the composite coatings was increased by increasing the tungsten carbide content. The cavitation erosion is mainly caused by removal of the matrix material. The steady-state erosion rates have a linear relationship with the volume fraction of the tungsten carbide phase.

Microstructures and Mechanical Properties of 6061 Al Matrix Smart Composite Containing TiNi Shape Memory Fiber

1996 ◽  
Vol 459 ◽  
Author(s):  
J. H. Lee ◽  
K. Hamada ◽  
K. Miziuuchia ◽  
M. Taya ◽  
K. Inoue
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Matrix Material ◽  
Matrix Alloy ◽  
Flow Strength ◽  
The Matrix ◽  
Shape Memory Fiber ◽  
Al Matrix

ABSTRACT6061 Al-matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by vacuum hot pressing to investigate the microstructure and mechanical properties. The yield stress of this composite increases with increasing amount of prestrain, and it also depends on the volume fraction of fiber and heat treatment. The smartness of the composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stresses in the matrix material when heated after being prestrained. Microstructual observations have revealed that interfacial reactions occur between the matrix and fiber, creating two intermetallic layers. The flow strength of the composite at elevated temperatures is significantly higher than that of the matrix alloy without TiNi fiber.

An analysis of piezoelectric composite materials containing ellipsoidal inhomogeneities

1993 ◽  
Vol 443 (1918) ◽  
pp. 265-287 ◽  
Keyword(s):  
Composite Materials ◽  
Effective Properties ◽  
Mean Field ◽  
Piezoelectric Medium ◽  
Piezoelectric Composite ◽  
High Concentration ◽  
Reinforced Composite ◽  
The Matrix ◽  
Eshelby’S Tensor ◽  
Piezoelectric Solids

A set of four tensors corresponding to Eshelby’s tensor in elasticity are obtained for an ellipsoidal inclusion embedded in an infinite piezoelectric medium. These tensors, which describe the elastic, piezoelectric, and dielectric constraint of the matrix, are obtained from W. F. Deeg’s solution to inclusion and inhomogeneity problems in piezoelectric solids. These tensors are then used as the backbone in the development of a micromechanics theory to predict the effective elastic, dielectric, and piezoelectric moduli of particle and fibre reinforced composite materials. The effects of interaction among inhomogeneities at finite concentrations are approximated through the Mori-Tanaka mean field approach. This approach, although widely utilized in the study of uncoupled elastic and dielectric behaviour, has not before been applied to the study of coupled behaviour. To help ensure confidence in the theory, the analytical predictions are proven to be self-consistent, diagonally symmetric, and to exhibit the correct behaviour in the low and high concentration limits. Finally, numerical results are presented to illustrate the effects of the concentration, shape, and material properties of the reinforcement on the effective properties of piezoelectric composites and analytical predictions are shown to result in good agreement with existing experimental data.

scholarly journals The AC and DC Conductivity of Nanocomposites

2007 ◽  
Vol 2007 ◽  
pp. 1-9 ◽  
Author(s):  
David S. McLachlan ◽  
Godfrey Sauti
Keyword(s):  
Electrical Properties ◽  
Volume Fraction ◽  
Matrix Material ◽  
Dc Conductivity ◽  
Critical Volume ◽  
Matrix Structure ◽  
Electrical Measurements ◽  
Conducting Component ◽  
Critical Volume Fraction ◽  
The Matrix

The microstructures of binary (conductor-insulator) composites, containing nanoparticles, will usually have one of two basic structures. The first is the matrix structure where the nanoparticles (granules) are embedded in and always coated by the matrix material and there are no particle-particle contacts. The AC and DC conductivity of this microstructure is usually described by the Maxwell-Wagner/Hashin-Shtrikman or Bricklayer model. The second is a percolation structure, which can be thought to be made up by randomly packing the two types of granules (not necessarily the same size) together. In percolation systems, there exits a critical volume fraction below which the electrical properties are dominated by the insulating component and above which the conducting component dominates. Such percolation systems are best analyzed using the two-exponent phenomenological percolation equation (TEPPE). This paper discusses all of the above and addresses the problem of how to distinguish among the microstructures using electrical measurements.

Modeling of the Effective Elastic Properties of Multifunctional Carbon Nanocomposites Due to Agglomeration of Straight Circular Carbon Nanotubes in a Polymer Matrix

2013 ◽  
Vol 81 (2) ◽  
Author(s):  
Chetan Shivaputra Jarali ◽  
Somaraddi R. Basavaraddi ◽  
Björn Kiefer ◽  
Sharanabasava C. Pilli ◽  
Y. Charles Lu
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Effective Properties ◽  
Transverse Isotropy ◽  
Effective Elastic Moduli ◽  
Effective Elastic Properties ◽  
The Matrix ◽  
Nanotube Composites

In the present study, the effective elastic properties of multifunctional carbon nanotube composites are derived due to the agglomeration of straight circular carbon nanotubes dispersed in soft polymer matrices. The agglomeration of CNTs is common due to the size of nanotubes, which is at nanoscales. Furthermore, it has been proved that straight circular CNTs provide higher stiffness and elastic properties than any other shape of the nanofibers. Therefore, in the present study, the agglomeration effect on the effective elastic moduli of the CNT polymer nanocomposites is investigated when circular CNTs are aligned straight as well as distributed randomly in the matrix. The Mori–Tanaka micromechanics theory is adopted to newly derive the expressions for the effective elastic moduli of the CNT composites including the effect of agglomeration. In this direction, analytical expressions are developed to establish the volume fraction relationships for the agglomeration regions with high, and dilute CNT concentrations. The volume of the matrix in which there may not be any CNTs due to agglomeration is also included in the present formulation. The agglomeration volume fractions are subsequently adopted to develop the effective relations of the composites for transverse isotropy and isotropic straight CNTs. The validation of the modeling technique is assessed with results reported, and the variations in the effective properties for high and dilute agglomeration concentrations are investigated.

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