Micromechanics of a Smart Composite Actuator Embedded With Hollow Piezoelectric Fibers

2011 ◽  
Author(s):  
Sontipee Aimmanee ◽  
Supharoek Trakarnkulchai ◽  
Pakinee Aimmanee
Keyword(s):  
Volume Fraction ◽  
Transversely Isotropic ◽  
Material System ◽  
Smart Composite ◽  
Concentric Cylinder ◽  
Fiber Volume ◽  
Reinforced Composite ◽  
Concentric Cylinders ◽  
Matrix Volume ◽  
Composite Actuator

This paper presents a development of mathematical models for predicting the effective elastic and piezoelectric properties of a Smart Composite Actuator (SCA) reinforced with transversely isotropic piezoelectric hollow fibers. The models are established based on micromechanics of representative volume element of concentric cylinders or so-called concentric cylinder model (CCM). Five elastic constants and two piezoelectric coefficients are predicted as a function of fiber volume fraction, matrix volume fraction, and their constituents’ properties in the SCA. Numerical results of a chosen material system are obtained and discussed. The models can be found useful for developing a SCA or a novel hollow fiber-reinforced composite with the desired properties.

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.

Locally Exact Homogenization of Unidirectional Composites With Cylindrically Orthotropic Fibers

2016 ◽  
Vol 83 (7) ◽  
Author(s):  
Guannan Wang ◽  
Marek-Jerzy Pindera
Keyword(s):  
Volume Fraction ◽  
Local Stress ◽  
Transversely Isotropic ◽  
Local Fields ◽  
Homogenization Theory ◽  
Classical Solutions ◽  
Equilibrium Equations ◽  
Fiber Volume ◽  
Unidirectional Composites ◽  
Cylindrically Orthotropic

The elasticity-based, locally exact homogenization theory for unidirectional composites with hexagonal and tetragonal symmetries and transversely isotropic phases is further extended to accommodate cylindrically orthotropic reinforcement. The theory employs Fourier series representations of the fiber and matrix displacement fields in cylindrical coordinate system that satisfy exactly equilibrium equations and continuity conditions in the interior of the unit cell. Satisfaction of periodicity conditions for the inseparable exterior problem is efficiently accomplished using previously introduced balanced variational principle which ensures rapid displacement solution convergence with relatively few harmonic terms. As demonstrated in this contribution, this also applies to cylindrically orthotropic reinforcement for which the eigenvalues depend on both the orthotropic elastic moduli and harmonic number. The solution's demonstrated stability facilitates rapid identification of cylindrical orthotropy's impact on homogenized moduli and local fields in wide ranges of fiber volume fraction and orthotropy ratios. The developed theory provides a unified approach that accounts for cylindrical orthotropy explicitly in both the homogenization process and local stress field calculations previously treated separately through a fiber replacement scheme. Comparison of the locally exact solution with classical solutions based on an idealized microstructural representation and fiber moduli replacement with equivalent transversely isotropic properties delineates their applicability and limitations.

scholarly journals TENSILE TEST ANALYSIS OF NATURAL FIBER REINFORCED COMPOSITE

2014 ◽  
pp. 148-152
Author(s):  
G. VELMURUGAN ◽  
D. VADIVEL ◽  
R. ARRAVIND ◽  
A. MATHIAZHAGAN ◽  
S.P. VENGATESAN
Keyword(s):  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Tensile Load ◽  
Experimental Result ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Test Analysis ◽  
Reinforced Composite ◽  
Strain Stress

This project mainly deals with analysis of tensile properties of Palmyra fiber Reinforced Epoxy Composite that is suitable for automobile application. First, the property of material was obtained on the basis of some assumptions (i.e., Rule of Mixture) and was modeled with reference to ASTM D638. Here the simulation was carried out on specimen under different fiber volume fraction and fiber length. The present work includes the Analysis of Palmyra Fiber Reinforced Epoxy Composites using FEA with various fiber volume fractions and these results were validated with the experimental result. The tensile property of Palmyra fiber composite material can be obtained by using tensometer.During the tensile load, the maximum strain, stress and displacement were obtained and, then this experimental result was compared with the analytical results and the error percentage of these results were calculated.

scholarly journals Design, Analysis and Manufacturing Polymer Fiber Reinforced Composite Helical Spring

2020 ◽  
Vol 23 (4) ◽  
pp. 338-344
Author(s):  
Hadeer Abdul Rasol Hamed ◽  
Mahmud Rasheed Ismail ◽  
Abdul Rahman Najam
Keyword(s):  
Volume Fraction ◽  
Fuel Efficiency ◽  
Fiber Reinforced Polymer ◽  
Light Weight ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Steel Spring ◽  
Reinforced Composite ◽  
Reinforced Polymer ◽  
Compression Spring

In this work it had been focused on the possibility of replacement of steel spring in suspension system by fiber reinforced polymer composite that is responsible for light weight of spring which leads to reduces the weight of vehicle and improve fuel efficiency. This type of spring used in motor cycles, light weight vehicle.  The design will be simulated by ANSYS workbench. Then, E-Glass fiber has been used to fabricate helical compression spring of 40%   fiber volume fraction of glass. with polyester resin. The deflection of glass reinforced composite spring is more than steel spring but within permissible limit. weight of composite spring is reduced by 57% than of steel.

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.

Development of a Constitutive Theory for Short Fiber Yarns: Mechanics of Staple Yarn Without Slippage Effect

1992 ◽  
Vol 62 (12) ◽  
pp. 749-765 ◽  
Author(s):  
Ning Pan
Keyword(s):  
Fiber Length ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Stress Transfer ◽  
Transversely Isotropic ◽  
Short Fiber ◽  
Constitutive Theory ◽  
Fiber Volume ◽  
Shear Moduli ◽  
Yarn Twist

This article reports an attempt to develop a general constitutive theory governing the mechanical behavior of twisted short fiber structures, starting with a high twist case, so that the effect of fiber slippage during yarn extension can be ignored. A differential equation describing the stress transfer mechanism in a staple yarn is proposed by which both the distributions of fiber tension and lateral pressure along a fiber length during yarn extension are derived. Factors such as fiber dimensions and properties and the effect of the discontinuity of fiber length within the structure are all included in the theory. With certain assumptions, the relationship between the mean fiber-volume fraction and the twist level of the yarn is also established. A quantity called the cohesion factor is defined based on yarn twist and fiber properties as well as on the form of fiber arrangement in the yarn to reflect the effectiveness of fiber gripping by the yarn. By considering the yarn structure as transversely isotropic with a variable fiber-volume fraction depending on the level of twist, the tensile and shear moduli as well as the Poisson's ratios of the structures are theoretically determined. All these predicted results have been verified according to the constitutive restraints of the continuum mechanics, and the final results are also illustrated schematically.

scholarly journals Pengaruh Penambahan Serat Batang Pisang Ketip dan Filler Dedak Padi Terhadap Density, Kekuatan Bending dan Tarik Kompositcore, Sandwich dengan Skin Plywood

MECHANICAL ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Salman Salman ◽  
Ahmad Fadly
Keyword(s):  
Tensile Strength ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Volume Fraction ◽  
Sandwich Composite ◽  
Fiber Direction ◽  
Fiber Volume ◽  
Banana Fiber ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Fiber-reinforced composite core banana stems with additional filler of husk powder is another way to obtain the expected mechanical behavior of the composite. The aim of this study was to analyze the effect of fiber volume fraction content to density, bending strength and tensile strength of sandwich composite.   Preparation of composite was done by hand lay-up method. Composite material used by banana ketip  fiber and addition of husk powder with variation of fiber volume fraction were 7, 10, and 13 % where husk was constant at 5% with random fiber direction. Tests were conducted by referring to the density est standard (ASTM C 271), bending est (ASTM C 393) and tensile test (ASTM D3039).  The result showed that the greater volume fraction of banana fiber, the lower the density value and the lower the bending strength. Whereas the tensile strength tended to increase as the volume fraction was higher.

Bending Properties of Four-Layer Biaxial Weft Knitted Fabric Reinforced Composite Materials

2012 ◽  
Vol 182-183 ◽  
pp. 89-92
Author(s):  
Liang Sen Liu ◽  
Ye Xiong Qi ◽  
Jia Lu Li
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Volume Fraction ◽  
Bending Properties ◽  
Fiber Volume ◽  
Reinforced Composite ◽  
Weft Knitted Fabric ◽  
Bending Load

In this paper, a kind of composite laminates whose reinforcement is four-layer biaxial weft knitted (FBWK)fabric made of carbon fiber as inserted yarns has been made. The composite laminates have been impregnated with epoxy resin via resin transfer molding (RTM) technique. The samples of the experiments have been made from the composite laminates. The bending properties of the FBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The results show that the bending strength of this kind of composites increases with the fiber volume fraction increasing. The bending strength of FBWK reinforced composites with fiber volume fraction of 52% can reach 695.86 MPa. And the relationship between bending load and deflection is obviously linear.

Sign in / Sign up

Export Citation Format

Share Document