scholarly journals Vibrational Study of Fluid-Filled Functionally Graded Cylindrical Shells Resting on Elastic Foundations

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Abdul Ghafar Shah ◽  
Tahir Mahmood ◽  
Muhammad Nawaz Naeem ◽  
Shahid Hussain Arshad
Keyword(s):  
Cylindrical Shells ◽  
Functionally Graded ◽  
Dynamical Equations ◽  
Graded Materials ◽  
Elastic Foundations ◽  
Present Technique ◽  
Vibrational Characteristics ◽  
Love’S Thin Shell Theory ◽  
Thin Shell Theory ◽  
Good Agreement

Vibrational characteristics of functionally graded cylindrical shells filled with fluid and placed on Winkler and Pasternak elastic foundations are investigated. Love's thin-shell theory is utilized for strain-displacement and curvature-displacement relationships. Shell dynamical equations are solved by using wave propagation approach. Natural frequencies for both empty and fluid-filled functionally graded cylindrical shells based on elastic foundations are determined for simply-supported boundary condition and compared to validate the present technique. Results obtained are in good agreement with the previous studies. It is seen that the frequencies of the cylindrical shells are affected much when the shells are filled with fluid, placed on elastic foundations, and structured with functionally graded materials. The influence of Pasternak foundation is more pronounced than that of Winkler modulus.

scholarly journals Vibration Characteristics of Ring-Stiffened Functionally Graded Circular Cylindrical Shells

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Muhmmad Nawaz Naeem ◽  
Shazia Kanwal ◽  
Abdul Ghafar Shah ◽  
Shahid Hussain Arshad ◽  
Tahir Mahmood
Keyword(s):  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Vibration Characteristics ◽  
Functionally Graded ◽  
Lagrangian Function ◽  
Dynamical Equations ◽  
Graded Materials ◽  
Present Technique ◽  
Circular Cylindrical Shells ◽  
Stiffened Cylindrical Shells

The vibration characteristics of ring stiffened cylindrical shells are analyzed. These shells are assumed to be structured from functionally graded materials (FGM) and are stiffened with isotropic rings. The problem is formulated by coupling the expressions for strain and kinetic energies of a circular cylindrical shell with those for rings. The Lagrangian function is framed by taking difference of strain and kinetic energies. The Rayleigh-Ritz approach is employed to obtain shell dynamical equations. The axial model dependence is approximated by characteristic beam functions that satisfy the boundary conditions. The validity and efficiency of the present technique are verified by comparisons of present results with the previous ones determined by other researchers.

Vibrations of Partially Fluid-Filled Functionally Graded Cylindrical Shells

2009 ◽  
Author(s):  
Mahdi Saeidifar ◽  
Abdolreza Ohadi
Keyword(s):  
Cylindrical Shells ◽  
Ritz Method ◽  
Functionally Graded ◽  
Arbitrary Boundary ◽  
Power Law Exponent ◽  
Graded Material ◽  
Love’S Thin Shell Theory ◽  
Thin Shell Theory ◽  
Theoretical Results ◽  
Kinetic And Potential Energies

In this study, the free vibration of partially fluid-filled functionally graded material (FGM) cylindrical shells with arbitrary boundary conditions has been investigated using the Rayleigh-Ritz method. The analysis has been carried out with strain-displacement relations from Love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. The Rayleigh-Ritz method is based on the energy parameters, so after determining the kinetic and potential energies of FGM shell filled with fluid, the eigenvalue problem has been obtained. To demonstrate the validity and accuracy of the obtained theoretical results, comparison has been made with the previous published results and also with the finite element results for the empty and partially fluid-filled shells. Finally, the effects of fluid level and power-law exponent on natural frequencies of partially fluid-filled FGM shells have been investigated.

Generalized displacement correlation method for mechanical and thermal fracture of FGM

2020 ◽  
Vol 09 (01) ◽  
pp. 2050004
Author(s):  
Y. Ait Ferhat ◽  
A. Boulenouar ◽  
N. Benamara ◽  
L. Benabou
Keyword(s):  
Present Method ◽  
Thermal Loading ◽  
Parametric Design ◽  
Correlation Method ◽  
Functionally Graded ◽  
Mixed Mode Fracture ◽  
Graded Materials ◽  
Displacement Based ◽  
Ansys Parametric Design Language ◽  
Good Agreement

The main objective of this work is to present a numerical modeling of mixed-mode fracture in isotropic functionally graded materials (FGMs), under mechanical and thermal loading conditions. In this paper, the displacement-based method, termed the generalized displacement correlation (GDC) method, is investigated for estimating stress intensity factor (SIF). Using the ANSYS Parametric Design Language (APDL), the continuous variations of the material properties are incorporated by specified parameters at the centroid of each element. This paper presents various numerical examples in which the accuracy of the present method is verified. Comparisons have been made between the SIFs predicted by the GDC method and the available reference solutions in the current literature. A good agreement is achieved between the results of the GDC method and the reference solutions.

Vibrations of functionally graded cylindrical shells based on elastic foundations

2009 ◽  
Vol 211 (3-4) ◽  
pp. 293-307 ◽  
Author(s):  
Abdul Ghafar Shah ◽  
Tahir Mahmood ◽  
Muhammad N. Naeem ◽  
Zafar Iqbal ◽  
Shahid H. Arshad
Keyword(s):  
Cylindrical Shells ◽  
Functionally Graded ◽  
Elastic Foundations

Calculation of Tape Thickness for Ceramic Tape Casting

2012 ◽  
Vol 512-515 ◽  
pp. 328-333 ◽  
Author(s):  
Shu Long Liu ◽  
Qiang Shen ◽  
Guo Qiang Luo ◽  
Mei Juan Li ◽  
Lian Meng Zhang
Keyword(s):  
Close Agreement ◽  
Tape Casting ◽  
Industrial Area ◽  
Functionally Graded ◽  
Experimental Measurements ◽  
Graded Materials ◽  
Rheological Models ◽  
Calculation Results ◽  
Ceramic Tape ◽  
Good Agreement

Tape casting play a significant role in industrial area, such as multilayered ceramic (MLC) packages, functionally graded materials (FGM), low temperature co-fired ceramics (LTCC) and so on. For the complexity of the rheology for slurry during tape casing process, the control of tape thickness by experience was unstable. Although few numerical and analytical studies on predicting the tape thickness have been done, but these efforts have focused on Newtonian, Bingham, Power law, respectively. There is no unified equation to calculate the tape thickness among different rheological models. In this paper, the calculation results are characterized by wide adaptability; the blade gap, the casting speed and the slurry rheological property are incorporated into calculation; the effect of parameters in the result is studied; Parameter Pnd can be used as a guide to check which mark patterns of the flow velocity profiles in the channel. The results proposed and the experimental measurements from existing publications are in close agreement. Compared with the prediction of the existing models, the calculation results proposed has good agreement with them.

scholarly journals Vibration and Buckling Analysis of Cylindrical Shells Made of Functionally Graded Materials under Combined Static and Periodic Axial Forces

2010 ◽  
Vol 19 (2) ◽  
pp. 096369351001900 ◽  
Author(s):  
F. Ebrahimi ◽  
H.A. Sepiani
Keyword(s):  
Transverse Shear ◽  
Volume Fraction ◽  
Cylindrical Shells ◽  
Shear Deformation Theory ◽  
Deformation Mode ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Graded Materials ◽  
Axial Forces ◽  
Graded Material

In this study, a formulation for the free vibration and buckling of cylindrical shells made of functionally graded material (FGM) subjected to combined static and periodic axial loadings are presented. The properties are temperature dependent and graded in the thickness direction according to a volume fraction power law distribution. The analysis is based on two different methods of first-order shear deformation theory (FSDT) considering the transverse shear strains and the rotary inertias and the classical shell theory (CST). The results obtained show that the effect of transverse shear and rotary inertias on vibration and buckling of functionally graded cylindrical shells is dependent on the material composition, the temperature environment, the amplitude of static load, the deformation mode, and the shell geometry parameters.

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