The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
A R Saidi - One of the best experts on this subject based on the ideXlab platform.
-
Levy-Type Solution for Bending-Stretching of Thick Functionally Graded Rectangular Plates Based on Third-Order Shear Deformation Theory
Mechanics of Advanced Materials and Structures, 2012Co-Authors: A R Saidi, Bodaghi, Seyed Rasoul AtashipourAbstract:In this article, an analytical approach for bending-stretching analysis of thick Functionally graded rectangular plates is presented. The governing equilibrium equations are obtained based on the third-order shear deformation plate theory. Introducing four new analytical Functions and doing some algebraic operations, five highly coupled governing equilibrium equations are converted into two independent partial differential equations in terms of transverse displacement and a new Function, called boundary Layer Function. Reformulated equations are solved analytically for the Functionally graded rectangular plates with two opposite edges simply supported. Some important numerical results for stress components, deflection, and the boundary Layer Function are presented.
-
The boundary Layer phenomenon in bending of thick annular sector plates
2010Co-Authors: Seyed Rasoul Atashipour, A R SaidiAbstract:Summary In this article, the bending equations of thick annular sector plates are derived based on the third-order shear deformation theory (TSDT). Using a Function, called boundary Layer Function, the coupled system of equations is converted into two decoupled equations and solved analytically. It is shown that the value of the boundary Layer Function for TSDT is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. It is seen that there exist no boundary Layer, a weak boundary Layer, and a strong boundary Layer effect for simply supported, clamped, and free edges, respectively.
-
on the boundary Layer phenomenon in bending of thick annular sector plates using third order shear deformation theory
Acta Mechanica, 2010Co-Authors: Seyed Rasoul Atashipour, A R Saidi, E JomehzadehAbstract:In this article, the bending equations of thick annular sector plates are extracted based on the third-order shear deformation theory. Using a Function, called boundary Layer Function, the coupled system of equations is converted into two decoupled equations. These equations are used to find a closed form solution for bending of thick transversely isotropic annular sector plates. It is shown that the solution of one of the decoupled equations has a boundary Layer behavior like that of Mindlin plate theory. It is seen that the value of the boundary Layer Function for third order shear deformation theory is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. Also, as in the Mindlin plate theory, there exist no boundary Layer, a weak boundary Layer, and a strong boundary Layer effect for simply supported, clamped, and free edges, respectively.
-
Bending analysis of thick laminated rectangular plates using a boundary Layer Function
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2010Co-Authors: A R Saidi, Seyed Rasoul Atashipour, H. KeshavarziAbstract:In this article, the governing bending equations of thick laminated transversely isotropic rectangular plates are derived based on third-order shear deformation theory (TSDT). Using a new Function, called the boundary Layer Function, the three coupled governing equations are converted to two decoupled equations. These equations are in terms of the deflection of the plate and the mentioned boundary Layer Function, which arewritten in invariant form. By solving the decoupled equations, a Levy-type analytical solution is presented for bending of a transversely isotropic plate. Finally, numerical results are presented for boundary Layer phenomenon and its effects in TSDT. It is shown that all of the boundary Layer effects in Mindlin-Reissner theory appear in this theory. However, it is shown that the intensity of the boundary Layer effects in TSDT exceeds that of theMindlin-Reissner theory.
-
On the stress singularities and boundary Layer in moderately thick Functionally graded sectorial plates
Applied Mathematical Modelling, 2010Co-Authors: A R Saidi, F. Hejripour, E JomehzadehAbstract:In this paper, the stress analysis of moderately thick Functionally graded sector plate is developed for studying the singularities in vicinity of the vertex and effects of boundary Layer. Based on the first-order shear deformation plate theory, the governing partial differential equations are obtained. Using an analytical method, the stretching and bending equilibrium equations are decoupled. Also, introducing a Function, called boundary Layer Function, the three bending equations are converted into two decoupled equations. These equations are solved analytically and the effects of boundary Layer Function on stress components are shown. Also, the singularities of shear force, moment resultants and boundary Layer Function are discussed for both salient ða 6 180Þ and re-entrant ða > 180Þ sectorial plates. In order to verify the accuracy of the results, the governing equations are also solved using differential quadrature method (DQM). By comparing the results of exact method with DQM, a good agreement can be seen.
E Jomehzadeh - One of the best experts on this subject based on the ideXlab platform.
-
on the boundary Layer phenomenon in bending of thick annular sector plates using third order shear deformation theory
Acta Mechanica, 2010Co-Authors: Seyed Rasoul Atashipour, A R Saidi, E JomehzadehAbstract:In this article, the bending equations of thick annular sector plates are extracted based on the third-order shear deformation theory. Using a Function, called boundary Layer Function, the coupled system of equations is converted into two decoupled equations. These equations are used to find a closed form solution for bending of thick transversely isotropic annular sector plates. It is shown that the solution of one of the decoupled equations has a boundary Layer behavior like that of Mindlin plate theory. It is seen that the value of the boundary Layer Function for third order shear deformation theory is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. Also, as in the Mindlin plate theory, there exist no boundary Layer, a weak boundary Layer, and a strong boundary Layer effect for simply supported, clamped, and free edges, respectively.
-
On the stress singularities and boundary Layer in moderately thick Functionally graded sectorial plates
Applied Mathematical Modelling, 2010Co-Authors: A R Saidi, F. Hejripour, E JomehzadehAbstract:In this paper, the stress analysis of moderately thick Functionally graded sector plate is developed for studying the singularities in vicinity of the vertex and effects of boundary Layer. Based on the first-order shear deformation plate theory, the governing partial differential equations are obtained. Using an analytical method, the stretching and bending equilibrium equations are decoupled. Also, introducing a Function, called boundary Layer Function, the three bending equations are converted into two decoupled equations. These equations are solved analytically and the effects of boundary Layer Function on stress components are shown. Also, the singularities of shear force, moment resultants and boundary Layer Function are discussed for both salient ða 6 180Þ and re-entrant ða > 180Þ sectorial plates. In order to verify the accuracy of the results, the governing equations are also solved using differential quadrature method (DQM). By comparing the results of exact method with DQM, a good agreement can be seen.
-
Analytical solution for free vibration of transversely isotropic sector plates using a boundary Layer Function
Thin-Walled Structures, 2009Co-Authors: E Jomehzadeh, A R SaidiAbstract:Abstract The exact analytical solution based on the Mindlin's plate theory is presented for the free vibration of a transversely isotropic sector plate. The plate has simply supported radial edges and arbitrary conditions along the circular edge. By introducing a boundary Layer Function, the three coupled governing equations of motion have been converted into two uncoupled equations. Solving the uncoupled equations and satisfying the boundary conditions yields an eigenvalue problem for finding the natural frequencies. Non-dimensional frequency parameter is presented for over a wide range of salient ( α ⩽180) and re-entrant (180 α ⩽360) angles, some thickness–radius ratios and different boundary conditions along the circular edge.
Seyed Rasoul Atashipour - One of the best experts on this subject based on the ideXlab platform.
-
Levy-Type Solution for Bending-Stretching of Thick Functionally Graded Rectangular Plates Based on Third-Order Shear Deformation Theory
Mechanics of Advanced Materials and Structures, 2012Co-Authors: A R Saidi, Bodaghi, Seyed Rasoul AtashipourAbstract:In this article, an analytical approach for bending-stretching analysis of thick Functionally graded rectangular plates is presented. The governing equilibrium equations are obtained based on the third-order shear deformation plate theory. Introducing four new analytical Functions and doing some algebraic operations, five highly coupled governing equilibrium equations are converted into two independent partial differential equations in terms of transverse displacement and a new Function, called boundary Layer Function. Reformulated equations are solved analytically for the Functionally graded rectangular plates with two opposite edges simply supported. Some important numerical results for stress components, deflection, and the boundary Layer Function are presented.
-
The boundary Layer phenomenon in bending of thick annular sector plates
2010Co-Authors: Seyed Rasoul Atashipour, A R SaidiAbstract:Summary In this article, the bending equations of thick annular sector plates are derived based on the third-order shear deformation theory (TSDT). Using a Function, called boundary Layer Function, the coupled system of equations is converted into two decoupled equations and solved analytically. It is shown that the value of the boundary Layer Function for TSDT is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. It is seen that there exist no boundary Layer, a weak boundary Layer, and a strong boundary Layer effect for simply supported, clamped, and free edges, respectively.
-
on the boundary Layer phenomenon in bending of thick annular sector plates using third order shear deformation theory
Acta Mechanica, 2010Co-Authors: Seyed Rasoul Atashipour, A R Saidi, E JomehzadehAbstract:In this article, the bending equations of thick annular sector plates are extracted based on the third-order shear deformation theory. Using a Function, called boundary Layer Function, the coupled system of equations is converted into two decoupled equations. These equations are used to find a closed form solution for bending of thick transversely isotropic annular sector plates. It is shown that the solution of one of the decoupled equations has a boundary Layer behavior like that of Mindlin plate theory. It is seen that the value of the boundary Layer Function for third order shear deformation theory is higher than that of the Mindlin theory. Thus, variations of stress components in the edge zone of the plate are more significant. Also, as in the Mindlin plate theory, there exist no boundary Layer, a weak boundary Layer, and a strong boundary Layer effect for simply supported, clamped, and free edges, respectively.
-
Bending analysis of thick laminated rectangular plates using a boundary Layer Function
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2010Co-Authors: A R Saidi, Seyed Rasoul Atashipour, H. KeshavarziAbstract:In this article, the governing bending equations of thick laminated transversely isotropic rectangular plates are derived based on third-order shear deformation theory (TSDT). Using a new Function, called the boundary Layer Function, the three coupled governing equations are converted to two decoupled equations. These equations are in terms of the deflection of the plate and the mentioned boundary Layer Function, which arewritten in invariant form. By solving the decoupled equations, a Levy-type analytical solution is presented for bending of a transversely isotropic plate. Finally, numerical results are presented for boundary Layer phenomenon and its effects in TSDT. It is shown that all of the boundary Layer effects in Mindlin-Reissner theory appear in this theory. However, it is shown that the intensity of the boundary Layer effects in TSDT exceeds that of theMindlin-Reissner theory.
F. Hejripour - One of the best experts on this subject based on the ideXlab platform.
-
On the stress singularities and boundary Layer in moderately thick Functionally graded sectorial plates
Applied Mathematical Modelling, 2010Co-Authors: A R Saidi, F. Hejripour, E JomehzadehAbstract:In this paper, the stress analysis of moderately thick Functionally graded sector plate is developed for studying the singularities in vicinity of the vertex and effects of boundary Layer. Based on the first-order shear deformation plate theory, the governing partial differential equations are obtained. Using an analytical method, the stretching and bending equilibrium equations are decoupled. Also, introducing a Function, called boundary Layer Function, the three bending equations are converted into two decoupled equations. These equations are solved analytically and the effects of boundary Layer Function on stress components are shown. Also, the singularities of shear force, moment resultants and boundary Layer Function are discussed for both salient ða 6 180Þ and re-entrant ða > 180Þ sectorial plates. In order to verify the accuracy of the results, the governing equations are also solved using differential quadrature method (DQM). By comparing the results of exact method with DQM, a good agreement can be seen.
Hiroshi Kanai - One of the best experts on this subject based on the ideXlab platform.
-
Regional myocardial Layer Function in Doxorubicin cardiomyopathy; clinical evaluation using novel ultrasonic Doppler method
1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102), 1Co-Authors: Yoshiro Koiwa, Hideichi Kamada, Hiroshi Kanai, K. Sugimura, F. Tezuka, Y. Saitoh, Hideyuki Honda, Kunio Shirato, Noriyoshi ChubachiAbstract:We examined whether the novel Doppler technique could be a sensitive diagnostic method for the histological deterioration of Doxorubicin cardiomyopathy (DoxCM). 25 patients with acute lymphoblastic leukaemia were examined for six years. Moreover, in Doxorubicin injected rabbits, histological damage was compared to the myocardial Layer Function by the Doppler technique. In normal subjects, myocardial Layer thickening occurred in a synchronized fashion during the cardiac cycle. However, in patients, it was characterized by the appearance of a non-Functioning Layer in the septum. The conventional echocardiography could not be sensitive enough to demonstrate the change in DoxCM. In contrast, the myocardial Layer Function by this novel method obviates subclinical change in the myocardium. The histological examination in rabbits verified the linear relationship between the myocardial damage and the myocardial Layer Function. We concluded that the novel Doppler technique could be a useful modality for the histological change in DoxCM.
-
Importance of regional myocardial Layer Function by phased tracking method in doxorubicin cardiomyopathy
1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027), 1Co-Authors: Yoshiro Koiwa, Hideichi Kamada, Y. Saitoh, Kunio Shirato, Hiroshi KanaiAbstract:We examined whether the novel high resolution Doppler technique "the phased tracking method" is useful for evaluating the Functional deterioration in doxorubicin cardiomyopathy (DoxCM) following 20 patients of hematological malignancies. In normal subjects, myocardial Layer thickening by the phased tracking method occurred homogeneously, i.e., no thinning was observed during systole, across the left ventricular wall. However, in patients, it was characterized by the appearance of non-Functioning Layers as well as by a decrease in systolic thickening. Conventional echocardiography is not sufficiently sensitive to demonstrate the changes in DoxCM. In contrast, the change in myocardial Layer Function was useful for showing increasing myocardial deterioration in DoxCM. The phased tracking method supplies useful diagnostic information for DoxCM.