eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
54
64
10.22055/jacm.2016.12330
12330
مقاله پژوهشی
Linear dynamic response of nanobeams accounting for higher gradient effects
Dario Abbondanza
1
Daniele Battista
2
Francescogiuseppe Morabito
3
Chiara Pallante
4
Raffaele Barretta
rabarret@unina.it
5
Raimondo Luciano
6
Francesco Marotti de Sciarra
7
Giuseppe Ruta
8
Dipartimento di ingegneria meccanica e aeronautica, “La Sapienza”, Rome, Italy
Dipartimento di ingegneria meccanica e aeronautica, “La Sapienza”, Rome, Italy
Dipartimento di ingegneria meccanica e aeronautica, “La Sapienza”, Rome, Italy
Dipartimento di ingegneria meccanica e aeronautica, “La Sapienza”, Rome, Italy
Dipartimento di strutture per l’ingegneria e l’architettura, Università degli Studi di Napoli “Federico II”, Naples, Italy
Dipartimento di ingegneria civile e meccanica, Università degli Studi di Cassino e del Lazio Meridionale, Cassino (FR), Italy
Dipartimento di strutture per l’ingegneria e l’architettura, Università degli Studi di Napoli “Federico II”, Naples, Italy
Dipartimento di ingegneria strutturale e geotecnica, “La Sapienza”, Rome, Italy
Linear dynamic response of simply supported nanobeams subjected to a variable axial force is assessed by Galerkin numerical approach. Constitutive behavior is described by three functional forms of elastic energy densities enclosing nonlocal and strain gradient effects and their combination. Linear stationary dynamics of nanobeams is modulated by an axial force which controls the global stiffness of nanostrucure and hence its angular frequencies. Influence of the considered elastic energy densities on dynamical response is investigated and thoroughly commented.
http://jacm.scu.ac.ir/article_12330_953353d6907f8a892358b0e268e7a5d4.pdf
Nanobeams
Higher gradient effects
Dynamic response
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
65
73
10.22055/jacm.2016.12331
12331
مقاله پژوهشی
Deflection of a hyperbolic shear deformable microbeam under a concentrated load
Bekir Akgöz
bekirakgoz@akdeniz.edu.tr
1
Ömer Civalek
civalek@yahoo.com
2
Akdeniz University Civil Eng. Dept.
Civil Engineering Dept.
Deflection analysis of a simply supported microbeam subjected to a concentrated load at the middle is investigated on the basis of a shear deformable beam theory and non-classical theory. Effects of shear deformation and small size are taken into consideration by hyperbolic shear deformable beam theory and modified strain gradient theory, respectively. The governing differential equations and corresponding boundary conditions are obtained by implementing minimum total potential energy principle. Navier-type solution is employed to achieve an analytical solution for deflections of simply supported homogeneous microbeams. The effects of shear deformation, material length scale parameter and slenderness ratio on the bending response of microbeams are investigated in detail.
http://jacm.scu.ac.ir/article_12331_74384370b62dc8eb7cffcaa6a11331d5.pdf
Bending
hyperbolic shear deformation theory
modified strain gradient theory
size dependency
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
74
79
10.22055/jacm.2016.12365
12365
مقاله پژوهشی
Time integration of rectangular membrane free vibration using spline-based differential quadrature
Sara Javidpoor
sara.javidpour73@gmail.com
1
Nassim Ale Ali
aleali@kmsu.ac.ir
2
Amer Kabi
kaabi_amer@kmsu.ac.ir
3
Bachelor’s degree student of department of marine engineering, Khorramshahr university of marine science and technology
Department of Marine Engineering, Khorramshahr University of Marine Science &amp; Technology
3Assistant professor of department of marine engineering, Khorramshahr university of marine science and technology
In this paper, numerical spline-based differential quadrature is presented for solving the boundary and initial value problems, and its application is used to solve the fixed rectangular membrane vibration equation. For the time integration of the problem, the Runge–Kutta and spline-based differential quadrature methods have been applied. The Runge–Kutta method was unstable for solving the problem, with large errors in its results, but the spline-based differential quadrature method obtained results that agree with the exact solution. The relative errors were calculated and investigated for different values of time and spatial nodes of discretisation. It seems that the spline-based differential quadrature method is proper for the full simulation of membrane vibration in both spatial and temporal solutions. For the time solving of the membrane vibration, conventional methods, such as the Runge–Kutta method, are not useful even if the time steps are considered too small.
http://jacm.scu.ac.ir/article_12365_152c0c23a43caac99f641951921f8c41.pdf
Runge–Kutta method
spline-based differential quadrature method
membrane vibration
Time integration
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
80
95
10.22055/jacm.2016.12366
12366
مقاله پژوهشی
Bending Analysis of Thick Isotropic Plates by Using 5th Order Shear Deformation Theory
Yuwaraj M. Ghugal
ghugal@rediffmail.com
1
Param D. Gajbhiye
gparam786@gmail.com
2
Head of Department of Applied Mechanics, Govt. College of EngineeringKarad, Shivaji University, Maharashtra-415124, India
M-TECH STUDENT
A 5<sup>th</sup> order shear deformation theory considering transverse shear deformation effect as well as transverse normal strain deformation effect is presented for static flexure analysis of simply supported isotropic plate. The assumed displacement field accounts for non-linear variation of in-plane displacements as well as transverse displacement through the plate thickness. The condition of zero transverse shear stresses on the upper and lower surface of plate is satisfied. Hence the present formulation does not require the shear correction factor generally associated with the first order shear deformable theory. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. Closed-form analytical solutions for simply supported square isotropic thick plates subjected to single sinusoidal distributed loads are obtained. Numerical results for static flexure analysis include the effects of side to thickness ratio and plate aspect ratio for simply supported isotropic plates. Numerical results are obtained using MATLAB programming. The results of present theory are in close agreement with those of higher order shear deformation theories and exact 3D elasticity solutions.
http://jacm.scu.ac.ir/article_12366_b9e3037fda12c4f05a83ea31f80271e6.pdf
Thick isotropic plate
5th order shear deformation theory
static flexure
transverse shear stress
transverse normal stress
Navier solution
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
96
117
10.22055/jacm.2016.12393
12393
مقاله پژوهشی
Concerning the Effect of a Viscoelastic Foundation on the Dynamic Stability of a Pipeline System Conveying an Incompressible Fluid
Vincent Olunloyo
vosoolunloyo@hotmail.com
1
Charles Osheku
charlesosheku2002@yahoo.com
2
Patrick Olayiwola
olayiwola_patrickshola@yahoo.com
3
Department of Systems Engineering, Faculty of Engineering, University of Lagos
Centre for Space Transport and Propulsion, National Space Research and Development Agency
Department of Mechanical & Biomedical Engineering, College of Engineering, Bells University of Technology
In this paper, we present an analytical method for solving a well-posed boundary value problem of mathematical physics governing the vibration characteristics of an internal flow propelled fluid-structure interaction where the pipeline segment is idealized as an elastic hollow beam conveying an incompressible fluid on a viscoelastic foundation. The effect of Coriolis and damping forces on the overall dynamic response of the system is investigated. In actuality, for a pipe segment supported at both ends and subject to a free motion, these two forces generate conjugate complex frequencies for all flow velocities. On employing integral transforms and complex variable functions, a closed form analytical expression is derived for the overall dynamic response. It is demonstrated that a concise mathematical expression for the natural frequency associated with any mode of vibration can be deduced from the algebraic product of the complex frequency pairs. By a way of comparative analysis for damping decrement physics reminiscent with laminated structures, mathematical expressions are derived to illustrate viscoelastic damping effects on dynamic stability for any flow velocity. The integrity of the analytical solution is verified and validated by confirming theresults in literature in appropriate asymptotic limits.
http://jacm.scu.ac.ir/article_12393_e710693b0a11a860990fe9728243a690.pdf
Analytical method
viscoelastic foundation
Coriolis and damping forces
conjugate complex frequency pairs and damping decrement physics
eng
Shahid Chamran University of Ahvaz
Journal of Applied and Computational Mechanics
2383-4536
2383-4536
2016-12-01
2
2
118
127
10.22055/jacm.2016.12414
12414
مقاله پژوهشی
Thermoelastic Analysis of Functionally Graded Hollow Cylinder Subjected to Uniform Temperature Field
Dilip Kamdi
navvanna@rediffmail.com
1
Navneet Lamba
navneetkumarlamba@gmail.com
2
Head Department of Mathematics, R.M. G. College, Saoli, Chandrapur, India
Head Deptt. of Mathematics
Shri Lemdeo Patil Mahavidyalaya, Nagpur, INDIA
This paper deals with the determination of displacement function and thermal stresses of a finite length isotropic functionally graded hollow cylinder subjected to uniform temperature field. The solution of the governing thermoelastic equation is obtained, as suggested by Spencer et al. for anisotropic laminates. Numerical calculations are also carried out for FGM (Functionally graded material) system consisting of ceramic Alumina (Al<sub>2</sub>O<sub>3</sub>), along with Nickel (Ni) as the metallic component varying with distance in one direction and illustrated graphically.
http://jacm.scu.ac.ir/article_12414_da0a0af7483523f15d52e8ed3d78cc51.pdf
Uniformly heated
Hollow cylinder
Thermoelastic stresses
Functionally graded material
Inverse problem