Loading...
Search for:
stability-map
0.007 seconds
Stability and dynamics of viscoelastic moving rayleigh beams with an asymmetrical distribution of material parameters
, Article Symmetry ; Volume 12, Issue 4 , 2020 ; won Jung, D ; Mohammad Sedighi, H ; Zur, K. K ; Habibi, M ; Safa, M ; Sharif University of Technology
MDPI AG
2020
Abstract
In this article, vibration of viscoelastic axially functionally graded (AFG) moving Rayleigh and Euler-Bernoulli (EB) beams are investigated and compared, aiming at a performance improvement of translating systems. Additionally, a detailed study is performed to elucidate the influence of various factors, such as the rotary inertia factor and axial gradation of material on the stability borders of the system. The material properties of the beam are distributed linearly or exponentially in the longitudinal direction. The Galerkin procedure and eigenvalue analysis are adopted to acquire the natural frequencies, dynamic configuration, and instability thresholds of the system. Furthermore, an...
On the vibrations and stability of moving viscoelastic axially functionally graded nanobeams
, Article Materials ; Volume 13, Issue 7 , 2020 ; Jung, D. W ; Mohammad Sedighi, H ; Zur, K. K ; Habibi, M ; Safa, M ; Sharif University of Technology
MDPI AG
2020
Abstract
In this article, size-dependent vibrations and the stability of moving viscoelastic axially functionally graded (AFG) nanobeams were investigated numerically and analytically, aiming at the stability enhancement of translating nanosystems. Additionally, a parametric investigation is presented to elucidate the influence of various key factors such as axial gradation of the material, viscosity coecient, and nonlocal parameter on the stability boundaries of the system. Material characteristics of the system vary smoothly along the axial direction based on a power-law distribution function. Laplace transformation in conjunction with the Galerkin discretization scheme was implemented to obtain...
Experimental study of continuous h2/air rotating detonations
, Article Combustion Science and Technology ; 2020 ; Fahim, M ; Farshchi, M ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
An experimental study of a lab scale rotating detonation combustor (RDC) has been conducted to identify and classify its modes of operation under different feeding conditions. The chamber uses air as oxidizer and hydrogen as fuel. The stability diagram of the RDC has been determined based on the detonation chamber Reynolds number and reactants mixture equivalence ratio values. The Reynolds number is based on the air volume flow rate, chamber annulus size, and the reactants mixture feeding slot area. Hence the effects of geometrical parameters and operational parameters on the detonation wave stability can be presented in a single stability map. This diagram identifies different zones in...
Experimental study of continuous H2/Air rotating detonations
, Article Combustion Science and Technology ; Volume 194, Issue 3 , 2022 , Pages 449-463 ; 00102202 (ISSN) ; Fahim, M ; Farshchi, M ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
An experimental study of a lab scale rotating detonation combustor (RDC) has been conducted to identify and classify its modes of operation under different feeding conditions. The chamber uses air as oxidizer and hydrogen as fuel. The stability diagram of the RDC has been determined based on the detonation chamber Reynolds number and reactants mixture equivalence ratio values. The Reynolds number is based on the air volume flow rate, chamber annulus size, and the reactants mixture feeding slot area. Hence the effects of geometrical parameters and operational parameters on the detonation wave stability can be presented in a single stability map. This diagram identifies different zones in...
Prediction of machining chatter based on FEM simulation of chip formation under dynamic conditions
, Article International Journal of Machine Tools and Manufacture ; Volume 50, Issue 7 , July , 2010 , Pages 611-620 ; 08906955 (ISSN) ; Movahhedy, M. R ; Sharif University of Technology
2010
Abstract
Machining chatter is an inherently nonlinear phenomenon that is affected by many parameters such as cutting conditions, tool geometry e.g., nose radius and clearance angle and frictional conditions at the tool/workpiece interface. Models for chatter prediction often ignore nonlinearities or introduce them through simple models for friction and geometry. In particular, the effect of chiptool interaction on the occurrence of chatter is not investigated thoroughly. This paper presents a novel approach for prediction of chatter vibration and for investigation of the effects of various conditions on the onset of chatter. This approach uses finite element simulation to investigate the...
Magneto-mechanical stability of axially functionally graded supported nanotubes
, Article Materials Research Express ; Volume 6, Issue 12 , 2019 ; 20531591 (ISSN) ; Mirtalebi, H ; Ahmadian, M. T ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
In this paper, size-dependent vibration analysis of axially functionally graded (AFG) supported nanotubes conveying nanoflow under longitudinal magnetic fields are performed, aiming at performance improvement of fluid-interaction nanosystems. Either the density or the elastic modulus of the AFG nanotube varies linearly or exponentially along the axial direction. Based on the nonlocal continuum theory, the higher-order dynamical equation of motion of the system is derived considering no-slip boundary condition. Galerkin discretization technique and eigenvalue analysis are implemented to solve the modeled equation. The validity of the simplified model is justified by comparing the results with...
Vibration control and manufacturing of intelligibly designed axially functionally graded cantilevered macro/micro-tubes
, Article 13th IFAC Workshop on Intelligent Manufacturing Systems, IMS 2019, 12 August 2019 through 14 August 2019 ; Volume 52, Issue 10 , 2019 , Pages 382-387 ; 24058963 (ISSN) ; Ebrahimi Mamaghani, A ; Ahmadian, M. T ; Barari A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In the last decade, extensive attention is devoted to intelligibly designed materials of macro/micro-structures containing the fluid flow. In this study, intelligent control and vibrational stability of cantilevered fluid conveying macro/micro-tubes utilizing axially functionally graded (AFG) materials are considered. The governing equation of motion of the system is derived based on modified couple stress theory and then is discretized using Galerkin method. A detailed investigation is carried out to elaborate the influence of various parameters such as material properties, axial compressive load, and Pasternak foundation on the dynamical behavior of the system, all of which are influential...
Magneto-mechanical stability of axially functionally graded supported nanotubes
, Article Materials Research Express ; Volume 6, Issue 12 , 2019 ; 20531591 (ISSN) ; Mirtalebi, H ; Ahmadian, M. T ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
In this paper, size-dependent vibration analysis of axially functionally graded (AFG) supported nanotubes conveying nanoflow under longitudinal magnetic fields are performed, aiming at performance improvement of fluid-interaction nanosystems. Either the density or the elastic modulus of the AFG nanotube varies linearly or exponentially along the axial direction. Based on the nonlocal continuum theory, the higher-order dynamical equation of motion of the system is derived considering no-slip boundary condition. Galerkin discretization technique and eigenvalue analysis are implemented to solve the modeled equation. The validity of the simplified model is justified by comparing the results with...
Vibration control and manufacturing of intelligibly designed axially functionally graded cantilevered macro/micro-tubes
, Article 13th IFAC Workshop on Intelligent Manufacturing Systems, IMS 2019, 12 August 2019 through 14 August 2019 ; Volume 52, Issue 10 , 2019 , Pages 382-387 ; 24058963 (ISSN) ; Ebrahimi Mamaghani, A ; Ahmadian, M. T ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In the last decade, extensive attention is devoted to intelligibly designed materials of macro/micro-structures containing the fluid flow. In this study, intelligent control and vibrational stability of cantilevered fluid conveying macro/micro-tubes utilizing axially functionally graded (AFG) materials are considered. The governing equation of motion of the system is derived based on modified couple stress theory and then is discretized using Galerkin method. A detailed investigation is carried out to elaborate the influence of various parameters such as material properties, axial compressive load, and Pasternak foundation on the dynamical behavior of the system, all of which are influential...