Begell House Inc.
Composites: Mechanics, Computations, Applications: An International Journal
CMCA
2152-2057
5
1
2014
FLEXURAL ANALYSIS OF FIBROUS COMPOSITE BEAMS UNDER VARIOUS MECHANICAL LOADINGS USING REFINED SHEAR DEFORMATION THEORIES
1-19
10.1615/CompMechComputApplIntJ.v5.i1.10
Atteshamuddin Shamshuddin
Sayyad
SRES's College of Engineering, Kopargaon-423601, Maharashtra, India
Yuwaraj M.
Ghugal
Department of Applied Mechanics, Government Engineering College, Karad-415124, Maharashtra State, India
R. R.
Borkar
Water Resource Department, Government of Maharashtra, Nashik-422003, Maharashtra, India
fibrous composite beam
shear deformation
transverse shear stress
shear correction factor
displacement-based theories
The present study deals with the flexural analysis of single-layer fibrous composite beams using
several displacement-based shear deformation theories. The theories accounts for the parabolic variation
of shear stress through the thickness of a beam, so that the shear correction factor is not
needed. The number of unknown variables in all the theories is the same as in the first-order shear
deformation theory. These theories utilize displacement models which contain polynomial, trigonometric,
hyperbolic, and exponential functions in terms of the thickness coordinate to represent the
displacement variation across the thickness. A unified displacement field is used to represent all the
theories. The governing differential equations and associated boundary conditions are obtained by
using the principle of virtual work. A static flexural analysis is carried out for simply supported
fibrous composite beams subjected to different mechanical loadings. The results obtained using all
the theories are compared with those obtained by exact elasticity solution for a sinusoidal load and
then their validity is checked for other loading conditions.
INVESTIGATION OF THE DYNAMIC BEHAVIOR OF FUNCTIONALLY GRADED MATERIAL UNDER DIFFERENT BOUNDARY CONDITIONS USING THE EULERâˆ’BERNOULLI THEORY
21-33
10.1615/CompMechComputApplIntJ.v5.i1.20
Mohammad Amin
Rashidifar
Faculty of Mechanical Engineering, Islamic Azad University, SHADEGAN Branch, SHADEGAN, Iran
Ali Amin
Rashidifar
Computer Science, Islamic Azad University, SHADEGAN Branch, SHADEGAN, Iran
functionally graded mateiral
finite element method
modal analysis
dynamic analysis
The technological advances in the engineering field require materials with improved mechanical properties. In material science, one of such ground breaking technologies is the functionally graded material (FGM). In order to use these materials for practical applications it is necessary to gain
a better understanding of their behavior. In the present work, the dynamic behavior of the FGM under different boundary conditions with material variation along the axial direction with respect to power exponent is investigated using two-dimensional finite element simulation. The modal
parameters are reported for each boundary condition. The frequency function of the FGM structure response to different loadings is also reported. The parametric study is carried out to observe the effect of power exponent on the modal parameters. It has been observed that an increase in the power exponent results in a decrease in the value of the fundamental natural frequency. This provides a
means of controlling the natural frequency of structure for avoiding resonance.
AVERAGING THE NONSTATIONARY EQUATIONS OF VISCOUS SUBSTANCE FILTRATION THROUGH A RIGID POROUS MEDIUM
35-61
10.1615/CompMechComputApplIntJ.v5.i1.30
Viktoria
Savatorova
Central Connecticut State University
Alexey
Talonov
UNLV, MEPhI
A. N.
Vlasov
Institute of Applied Mechanics, Russian Academy of Sciences,
7 Leningradsky Ave., Moscow, 125040, Russian Federation
Dmitriy B.
Volkov-Bogorodsky
Institute of Applied Mechanics, Russian Academy of Sciences, 7 Leningradsky
Ave., Moscow, 125040, Russia
filtration
Brinkman equation
porous media
homogenization
asymptotic averaging technique
unsteady flow
nonlinearity
The asymptotic averaging technique is used to solve the equations describing filtration of viscous compressible barotropic substance in a medium with a periodic structure of pores. As the equation of motion, we consider generalization of the Brinkman equation to the case of a possible unsteady flow of a fluid, which takes into account the nonlinear effects related to the dependence of the viscosity and friction coefficients on pressure. The effective permeability tensor is found in the course
of solution on the periodicity cell of the corresponding problems and their subsequent averaging.
The results of analytical and numerical-analytical solutions of the problem on a cell in one- and
three-dimensional cases, respectively, are presented. The distributions of pressure and velocity in
zero approximation are found by solving an averaged macroscopic equation. The effect of different types of dependences of viscosity and friction coefficients on pressure, as well as different types of barotropic relations between density and pressure is investigated.
THE INFLUENCE OF THE STRAIN RATE ON ULTIMATE PROPERTIES OF POLYMERS AND EXPERIMENTAL VERIFICATION OF THE LONG-TERM STRENGTH CRITERIA
63-75
10.1615/CompMechComputApplIntJ.v5.i1.40
Yu. P.
Zezin
Institute of Mechanics at the M. V. Lomonosov Moscow State University, Moscow, Russia
polymers
deformation
fracture
strain rate
long-term strength
criteria of fracture
tension; complex stressed state
It was shown that the mechanical properties of polymers greatly depend on the strain rate. Such dependence makes it difficult to use the ultimate characteristics as criterial parameters for predicting the conditions of fracture of products and parts from polymers. It was suggested to generalize the previously formulated energy criterion of long-term strength of polymers to the case of complex
stressed state. The results of the experimental verification of this criterion and its comparison with
the known deformation criterion of fracture based on the data of testing of two polymers of different classes under tension and complex stressed state in deformation with a step program of strain range variation within several decimal exponents are presented.
SELF-CONSISTENT SOLUTIONS FOR ELECTROMAGNETIC COUPLING COEFFICIENTS OF FIBROUS PIEZOCOMPOSITE
77-88
10.1615/CompMechComputApplIntJ.v5.i1.50
A. A.
Pankov
Perm National Research Polytechnic University, Perm, Russian Federation
piezocomposite
boundary-value problem of electromagnetic elasticity
effective properties
self-consistency scheme
New analytical solutions for 11 effective electromagnetic and elastic constants of a unidirectional fibrous composite with various polydispersed structures are obtained based on the self-consistency principle of composite mechanics. Numerical calculations and analysis of the volumetric content of fibers and inversion of the properties of phases (compared to the known solutions of the generalized
singular approximation for a statistical mixture and the method of asymptotic averaging for the ideal periodic structure) as well as their influence on the effective constants of a composite with piezoelectric PVF fibers in a ferrite piezomagnetic matrix are performed.