Dynamic Analysis of Heterogeneous Pressure Vessels Subjected to Thermomechanical Loads

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
F. Alisafaei ◽  
R. Ansari
Keyword(s):  
Material Properties ◽  
Present Method ◽  
Pressure Vessels ◽  
Functionally Graded ◽  
Elastic Analysis ◽  
Stress Distributions ◽  
Thick Hollow Cylinder ◽  
Graded Material ◽  
The Finite Difference Method ◽  
Existing Data

The elastic analysis of two different kinds of radially heterogeneous pressure vessels is conducted in this paper. As a first kind of heterogeneous pressure vessels, a multilayered pipe with different material properties in different layers is considered. Another kind of heterogeneous pressure vessels is a thick hollow cylinder made of functionally graded material (FGM). On the basis of the finite difference method, the time-dependent deformation, strain and stress distributions of both kinds of heterogeneous pipes are obtained under the different kinds of thermomechanical loadings. In this investigation, it is assumed that the pressure and temperature are symmetrical about the axis of the cylinder. Also, the material properties are considered to be independent of temperature. Results obtained from the present method are compared with the existing data.

Geometrically nonlinear dynamic response and vibration of shear deformable eccentrically stiffened functionally graded material cylindrical panels subjected to thermal, mechanical, and blast loads

2018 ◽  
Vol 22 (3) ◽  
pp. 658-688 ◽  
Author(s):  
Nguyen Dinh Duc ◽  
Ngo Duc Tuan ◽  
Pham Hong Cong ◽  
Ngo Dinh Dat ◽  
Nguyen Dinh Khoa
Keyword(s):  
Dynamic Response ◽  
Functionally Graded Material ◽  
Material Properties ◽  
Nonlinear Dynamic ◽  
Functionally Graded ◽  
Blast Loads ◽  
Temperature Dependent ◽  
Nonlinear Dynamic Response ◽  
Cylindrical Panels ◽  
Graded Material

Based on the first order shear deformation shell theory, this paper presents an analysis of the nonlinear dynamic response and vibration of imperfect eccentrically stiffened functionally graded material (ES-FGM) cylindrical panels subjected to mechanical, thermal, and blast loads resting on elastic foundations. The material properties are assumed to be temperature-dependent and graded in the thickness direction according to simple power-law distribution in terms of the volume fractions of the constituents. Both functionally graded material cylindrical panels and stiffeners having temperature-dependent properties are deformed under temperature, simultaneously. Numerical results for the dynamic response of the imperfect ES-FGM cylindrical panels with two cases of boundary conditions are obtained by the Galerkin method and fourth-order Runge–Kutta method. The results show the effects of geometrical parameters, material properties, imperfections, mechanical and blast loads, temperature, elastic foundations and boundary conditions on the nonlinear dynamic response of the imperfect ES-FGM cylindrical panels. The obtained numerical results are validated by comparing with other results reported in the open literature.

Stochastic Extended Finite Element Implementation for Natural Frequency of Cracked Functionally Gradient and Bi-Material Structures

2020 ◽  
pp. 2150044
Author(s):  
Ahmed Raza ◽  
Himanshu Pathak ◽  
Mohammad Talha
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Material Properties ◽  
Perturbation Technique ◽  
Vibration Characteristics ◽  
Functionally Graded ◽  
Extended Finite Element ◽  
Material Interface ◽  
Level Set Function ◽  
Graded Material

In this work, stochastic perturbation-based vibration characteristics of cracked bi-material and functionally graded material (FGM) domain with uncertain material properties are investigated using the extended finite element method. The level set function is implemented to track the geometrical discontinuities. The partition of unity-based extrinsic enrichment technique is employed to model the crack and material interface. The exponential law is used to model the graded material properties of FGM. The First-order perturbation technique (FOPT) is implemented to predict the standard deviation of natural frequency for the given uncertainties in the material properties. The numerical results are presented to show the effect of geometrical discontinuities and material randomness on vibration characteristics.

The Homogenized Transformation Method for the Calculation of Stress Intensity Factor in Cracked FGM Structure

2020 ◽  
pp. 2050014
Author(s):  
Rong LI ◽  
Meng Yang ◽  
Bin Liang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Functionally Graded Material ◽  
Calculation Method ◽  
Present Method ◽  
Transformation Method ◽  
Functionally Graded ◽  
Empirical Formulas ◽  
Graded Material

A convenient calculation method is proposed for the stress intensity factor (SIF) in cracked functionally graded material (FGM) structures. In this method, the complex computational problem for SIFs in cracked FGM plate and cylinder can be simplified as the calculation problem of empirical formulas of SIFs in cracked homogenous plate and cylinder with same loading conditions and the calculation problem of related transition parameters. The results show that the SIF in cracked FGM structure can be obtained accurately without using matrix and integral. The validity and usefulness of the present method are proved by comparing with the results of the conventional method.

Free Vibration and Elastic Critical Load of Functionally Graded Material Thin Cylindrical Shells Under Internal Pressure

2018 ◽  
Vol 18 (11) ◽  
pp. 1850138 ◽  
Author(s):  
Yueyang Han ◽  
Xiang Zhu ◽  
Tianyun Li ◽  
Yunyan Yu ◽  
Xiaofang Hu
Keyword(s):  
Cylindrical Shell ◽  
Free Vibration ◽  
Internal Pressure ◽  
Critical Load ◽  
Natural Frequency ◽  
Functionally Graded Material ◽  
Present Method ◽  
Cylindrical Shells ◽  
Functionally Graded ◽  
Graded Material

An analytical approach for predicting the free vibration and elastic critical load of functionally graded material (FGM) thin cylindrical shells filled with internal pressured fluid is presented in this study. The vibration of the FGM cylindrical shell is described by the Flügge shell theory, where the internal static pressure is considered as the prestress term in the shell equations. The motion of the internal fluid is described by the acoustic wave equation. The natural frequencies of the FGM cylindrical shell under different internal pressures are obtained with the wave propagation method. The relationship between the internal pressure and the natural frequency of the cylindrical shell is analyzed. Then the linear extrapolation method is employed to obtain the elastic critical load of the FGM cylindrical shell from the condition that the increasing pressure has resulted in zero natural frequency. The accuracy of the present method is verified by comparison with the published results. The effects of gradient index, boundary conditions and structural parameters on the elastic critical load of the FGM cylindrical shell are discussed. Compared with the experimental and numerical analyses based on the external pressure, the present method is simple and easy to carry out.

Distribution Parameter Optimization of an FGM Pressure Vessel

2011 ◽  
Vol 320 ◽  
pp. 404-409
Author(s):  
Ze Wu Wang ◽  
Shu Juan Gao ◽  
Qian Zhang ◽  
Pei Qi Liu ◽  
Xiao Long Jiang
Keyword(s):  
Analytical Solution ◽  
Pressure Vessel ◽  
Material Properties ◽  
Optimization Design ◽  
Optimal Solution ◽  
Functionally Graded ◽  
Material Distribution ◽  
Optimization Scheme ◽  
Graded Material ◽  
Optimal Material

Functionally graded material (FGM) is well-known as one of the most promising materials in the 21stcentury, which has become the hot issue on its mechanical behavior and composition design. The optimization design of the material distribution properties for an FGM hollow vessel subjected to internal pressure were investigated in this paper. By constructing an exponentially function determining the material properties, the general analytical solution of the stresses of the FGM pressure vessel was given based on the Euler-Cauchy formula. And then, an optimization model for obtaining the optimal material distribution of FGM vessel was proposed coupling the general finite element (FE) code. The discrepancy between the analytical solution and the numerical solution was about 2%, which verified the reliability of the proposed models, and the optimization results also proved the feasibility of proposed optimization scheme because of arriving at the optimal solution in a few iterations. Results obtained would be helpful in designing an FGM pressure vessel.

Homotopy Perturbation Method for Nonlinear Vibration Analysis of Functionally Graded Plate

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Ali A. Yazdi
Keyword(s):  
Perturbation Method ◽  
Material Properties ◽  
Homotopy Perturbation Method ◽  
Initial Conditions ◽  
Order Approximation ◽  
Oscillation Amplitude ◽  
Functionally Graded ◽  
Homotopy Perturbation ◽  
Graded Material ◽  
First Order Approximation

In this paper, the Homotopy perturbation method (HPM) is used to analysis the geometrically nonlinear vibrations of thin rectangular laminated functionally graded material (FGM) plates. The Von Karman's strain-displacement relations have been employed to model structural nonlinearity of the system. The material properties of the plate are assumed to be graded continuously in direction of thickness. The effects of initial deflection, aspect ratio and material properties are investigated. Based on the results of this study, the first order approximation of the HPM leads to highly accurate solutions for geometrically nonlinearity vibration of FGM plates. Moreover, HPM in comparison with other traditional analytical methods (e.g., perturbation methods) has excellent accuracy for the whole range of oscillation amplitude and initial conditions.

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