eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
199
213
514371
Wave Propagation in Mixture of Generalized Thermoelastic Solids Half-Space
R Kumar
rajneesh_kuk@rediffmail.com
1
S Devi
2
Department of Mathematics, Kurukshetra University
Department of Mathematics, D.N. College
This paper concentrates on the reflection of plane waves in the mixture of generalized thermo elastic solid half-space. There exists quasi dilatational waves i.e. <em>qP</em><sub>1</sub>, <em>qP</em><sub>2</sub>, <em>qT</em> and two rotational waves <em>S</em><sub>1</sub>, <em>S</em><sub>2</sub> in a two dimensional model of the solid. The boundary conditions are solved to obtain a system of five non-homogeneous equations for amplitude ratios. These amplitude ratios are found to depend on the angle of incidence of incident wave, mixture and thermal parameters and have been computed numerically and presented graphically. The appreciable effects of mixtures and thermal on the amplitude ratios are obtained.
http://jsm.iau-arak.ac.ir/article_514371_f7a3a4944e0c44258d2294ae746170e2.pdf
Dynamic theory of mixture
Amplitude ratios
Thermoelasticity
Wave propagation
Relaxation time
Reflection
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
214
230
514372
An Exact Solution for Lord-Shulman Generalized Coupled Thermoporoelasticity in Spherical Coordinates
M Jabbari
mjabbari@oiecgroup.com
1
H Dehbani
2
Postgraduate School, South Tehran Branch, Islamic Azad University
Sama Technical and Vocational Training School, Islamic Azad University, Varamin Branch
In this paper, the generalized coupled thermoporoelasticity model of hollow and solid spheres under radial symmetric loading condition (<em>r</em>, <em>t</em>) is considered. A full analytical method is used and an exact unique solution of the generalized coupled equations is presented. The thermal, mechanical and pressure boundary conditions, the body force, the heat source and the injected volume rate per unit volume of a distribute water source are considered in the most general forms and where no limiting assumption is used. This generality allows simulate varieties of applicable problems. At the end, numerical results are presented and compared with classic theory of thermoporoelasticity.
http://jsm.iau-arak.ac.ir/article_514372_7548494846a3a01cd3366b998f35d6ae.pdf
Coupled Thermoporoelasticity
Lord-shulman
Hollow sphere
Exact solution
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
231
247
514373
Finite Element Modeling of Crack Initiation Angle Under Mixed Mode (I/II) Fracture
S.S Bhadauria
ssb.aero@gmail.com
1
K.K Pathak
2
M.S Hora
3
Department of Applied Mechanics, Maulana Azad National Institute of Technology Bhopal
Advanced Materials Processes Research Institute (CSIR)
Department of Applied Mechanics, Maulana Azad National Institute of Technology Bhopal
Present study deals with the prediction of crack initiation angle for mixed mode (I/II) fracture using finite element techniques and <em>J</em>-Integral based approach. The FE code ANSYS is used to estimate the stress intensity factor numerically. The estimated values of SIF were incorporated into six different crack initiation angle criteria to predict the crack initiation angle. Single edge crack specimens of Araldite-Hardener were used for the present analysis. Load was applied up to critical limit of the specimens containing crack at different angles of inclination. The crack initiation angle obtained using stress intensity factor and <em>J</em>-integral based approach were found close to each other and also found to be in good agreement with the available experimental results in literature. It is also investigated that as crack inclination angle increases material was found to behave in a brittle manner.
http://jsm.iau-arak.ac.ir/article_514373_bf9df15dd9414f4327175ef008a5dd1d.pdf
Finite Element Method
Mixed mode fracture
Stress Intensity Factor
J-integral
Crack initiation angle
Fracture criteria
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
248
256
514382
Investigation of Vacancy Defects on the Young’s Modulus of Carbon Nanotube Reinforced Composites in Axial Direction via a Multiscale Modeling Approach
M.R Davoudabadi
davoudabadi.m@gmail.com
1
S.D Farahani
2
Department of Mechanical Engineering, Semnan University
Department of Mechanical Engineering, University of Tehran
In this article, the influence of various vacancy defects on the Young’s modulus of carbon nanotube (CNT) - reinforcement polymer composite in the axial direction is investigated via a structural model in ANSYS software. Their high strength can be affected by the presence of defects in the nanotubes used as reinforcements in practical nanocomposites. Molecular structural mechanics (MSM)/finite element (FE) Multiscale modeling of carbon nanotube/polymer composites with linear elastic polymer matrix is used to study the effect of CNT vacancy defects on the mechanical properties. The nanotube is modeled at the atomistic scale using MSM, where as the interface we assumed to be bonded by Vander Waals interactions based on the Lennar-Jonze potential at the interface and polymer matrix. A nonlinear spring is used for modeling of interactions. It is studied for zigzag and armchair Nanotubes with various aspect ratios (Length/Diameter). Finally, results of the present structural model show good agreement between our model and the experimental work.
http://jsm.iau-arak.ac.ir/article_514382_cdf8eb06c9a882ddc935c6f2d8522f61.pdf
Polymer matrix
Carbon nanotubes
Nonlinear spring
Multiscale modeling
Defect
Inter-phase
Finite element model
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
257
266
514383
Prediction of Crack Initiation Direction for Inclined Crack Under Biaxial Loading by Finite Element Method
P.C Gope
pcgope@rediffmail.com
1
S.P Sharma
2
A.K Srivastava
3
Department of Mechanical Engineering, College of Technology, G. B. Pant University of Agriculture and Technology
Mechanical Engineering Department, National Institute of Technology, Jamshedpur, Jharkhand
Deputy Manager (Design) Air Craft Upgrade Research and Design Centre, Hindustan Aeronautics Limited
This paper presents a simple method based on strain energy density criterion to study the crack initiation angle by finite element method under biaxial loading condition. The crack surface relative displacement method is used to eliminate the calculation of the stress intensity factors which are normally required. The analysis is performed using higher order four node quadrilateral element. The results by finite element method are compared with DET (determinant of stress tensor criterion) and strain energy density criteria. Finite element results are in well agreement with the experimental and analytical results.
http://jsm.iau-arak.ac.ir/article_514383_ef21a64defe321d89d36f2e7467189e7.pdf
Biaxial loading
mixed mode
Crack Initiation
Finite Element Method
Crack tip displacement
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
267
274
514384
Free Vibration Analysis of Micropolar Thermoelastic Cylindrical Curved Plate in Circumferential Direction
G Partap
gp.recjal@gmail.com
1
R Kumar
rajneesh_kuk@rediffmail.com
2
Department of Mathematics, Dr. B.R. Ambedkar National Institute of Technology, Jalandhar, Punjab
Department of Mathematics, Kurukshetra University
The free vibration analysis ofhomogeneous isotropic micropolar thermoelastic cylindrical curved plate in circumferential direction has been investigated in the context of generalized themoelasticity III, recently developed by Green and Naghdi. The model has been simplified using Helmholtz decomposition technique and the resulting equations have been solved using separation of variable method. Mathematical modeling of the problem to obtain dispersion curves for curved isotropic plate leads to coupled differential equations and solutions are obtained by using Bessel functions. The frequency equations connecting the frequency with circumferential wave number and other physical parameters are derived for stress free cylindrical plate. In order to illustrate theoretical development, numerical solutions are obtained and presented graphically for a magnesium crystal.
http://jsm.iau-arak.ac.ir/article_514384_1561a0a4220ae0862333fee63572297a.pdf
Micropolar
Phase velocity
Circumferential wave number
Thermoelasticity type III
Thermoelasticity without energy dissipation
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
275
289
514385
Review of Damage Tolerant Analysis of Laminated Composites
X.L Fan
fanxueling@mail.xjtu.edu.cn
1
Q Sun
2
M Kikuchi
3
State Key Laboratory for Mechanical Structural Strength and Vibration, School of Aerospace, Xi’an Jiao Tong University
School of Aeronautics, Northwestern Polytechnical University
Faculty of Science and Engineering, Tokyo University of Science
With advanced composites increasing replacing traditional metallic materials, the material inhomogeneity and inherent anisotropy of such materials lead to not only new attributes for aerospace structures, but also introduce new technology to damage tolerant design and analysis. The deleterious effects of changes in material properties and initiation and growth of structural damage must be addressed. The anisotropic and brittle properties make this requirement a challenging to composite structural designers. Accurate, reliable and user-friendly computational methods, design and analysis methods are vital for more damage tolerant composite structures. Both durability and damage tolerant methodologies must address the possible changes in mechanical properties and the evolving damage accumulations that may occur during the vehicle’s service lifetime. Delamination is a major failure mode in laminated composites and has received much research attention. It may arise out of manufacturing defects, free edge effects, structural discontinuities, low and high velocity impact damage, and even bird strikes. Early pioneering work established that the reduction in strength following delamination damages placed severe limits on the design allowable for highly loaded components such as aircraft wing and fuselage structure. In the present article, we provide a state-of-art survey on damage tolerant design correlated failure behavior and analysis methodologies of laminated composites. Particular emphasis is placed on some advanced formulations and numerical approaches for efficient computational modeling and damage tolerant analysis of laminated composites.
http://jsm.iau-arak.ac.ir/article_514385_283ccb9380274632a0095bf0d23cfcec.pdf
Damage tolerant analysis
Delamination
Virtual crack closure-integral technique
Cohesive zone model
Progressive failure analysis
eng
Islamic Azad University Arak Branch
Journal of Solid Mechanics
2008-3505
2008-7683
2010-09-30
2
3
290
304
514386
Static Analysis of Functionally Graded Annular Plate Resting on Elastic Foundation Subject to an Axisymmetric Transverse Load Based on the Three Dimensional Theory of Elasticity
A Behravan Rad
ahmadbehravan@yahoo.com
1
A Alibeigloo
2
S.S Malihi
3
Department of Mechanical Engineering, Islamic Azad University, Karaj Branch
Department of Mechanical Engineering, Engineering Faculty, Tarbiat Modares University
Department of Mechanical Engineering, Islamic Azad University, Karaj Branch
In this paper, static analysis of functionally graded annular plate resting on elastic foundation with various boundary conditions is carried out by using a semi-analytical approach (SSM-DQM). The differential governing equations are presented based on the three dimensional theory of elasticity. The plate is assumed isotropic at any point, while material properties to vary exponentially through the thickness direction and the Poisson’s ratio remain constant. The system of governing partial differential equations can be writhen as state equations by expanding the state variables and using the state space method (SSM) about thickness direction and applying the one dimensional differential quadrature method (DQM) along the radial direction. Interactions between the plate and two parameter elastic foundations are treated as boundary conditions. The stresses and displacements distributions are obtained by solving these state equations. In this study, the influences of the material property graded index, the elastic foundation coefficients (Winkler-Pasternak), the thickness to radius ratio, and edge supports effect on the bending behavior of the FGM annular plate are investigated and discussed in details.
http://jsm.iau-arak.ac.ir/article_514386_a534f52a3e74aaac7b5b248e94d13296.pdf
FGM annular Plate
Elastic foundation
Semi-Analytical Method
differential quadrature
state space