Nonlinear Thermo-Mechanical Stability Analysis of Eccentrically Spiral Stiffened Sandwich Functionally Graded Cylindrical Shells Subjected to External Pressure

2019 ◽  
Vol 11 (05) ◽  
pp. 1950045 ◽  
Author(s):  
Vu Hoai Nam ◽  
Nguyen Thi Phuong ◽  
Cao Van Doan ◽  
Nguyen Thoi Trung
Keyword(s):  
Mechanical Stability ◽  
Thermal Environment ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
External Pressure ◽  
Functionally Graded ◽  
Geometrical Parameters ◽  
Nonlinear Buckling ◽  
Circular Cylindrical Shells ◽  
The Galerkin Method

A new analytical approach to investigate the nonlinear buckling and postbuckling of the sandwich functionally graded circular cylindrical shells reinforced by ring and stringer or spiral stiffeners subjected to external pressure is presented in this paper. By employing the Donnell shell theory, the geometrical nonlinearity in Von Kármán sense and developed Lekhnitskii’s smeared stiffener technique, the governing equations of sandwich functionally graded circular cylindrical shells are derived. Resulting equations are solved by applying the Galerkin method to obtain the explicit expression of critical buckling external pressure load and postbuckling load–deflection curve. Effects of spiral stiffeners, thermal environment, external pressure, and geometrical parameters on nonlinear buckling behavior of sandwich functionally graded circular cylindrical shells are shown in numerical results.

scholarly journals An analytical approach to analyze nonlinear dynamic response of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure. Part 1: Governing equations establishment

2014 ◽  
Vol 36 (3) ◽  
pp. 201-214
Author(s):  
Dao Van Dung ◽  
Vu Hoai Nam
Keyword(s):  
Axial Compression ◽  
Nonlinear Dynamic ◽  
Analytical Approach ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
External Pressure ◽  
Functionally Graded ◽  
Time Dependent ◽  
Nonlinear Buckling ◽  
Circular Cylindrical Shells

Based on the classical thin shell theory with the geometrical nonlinearity in von Karman-Donnell sense, the smeared stiffener technique and Galerkin method, this paper deals with the nonlinear dynamic problem of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure by analytical approach. The present novelty is that an approximate three-term solution of deflection taking into account the nonlinear buckling shape is chosen, the nonlinear dynamic second-order differential three equations system is established and the frequency-amplitude relation of nonlinear vibration is obtained in explicit form.

scholarly journals Nonlinear Buckling Behavior of Spiral Corrugated Sandwich FGM Cylindrical Shells Surrounded by an Elastic Medium

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1984
Author(s):  
Vu Tho Hung ◽  
Dang Thuy Dong ◽  
Nguyen Thi Phuong ◽  
Le Ngoc Ly ◽  
Tran Quang Minh ◽  
...  
Keyword(s):  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
Equation System ◽  
External Pressure ◽  
Functionally Graded ◽  
Homogenization Theory ◽  
Nonlinear Buckling ◽  
Solution Form ◽  
Buckling Behavior ◽  
The Galerkin Method

This paper presents a semi-analytical approach for investigating the nonlinear buckling and postbuckling of spiral corrugated sandwich functionally graded (FGM) cylindrical shells under external pressure and surrounded by a two-parameter elastic foundation based on Donnell shell theory. The improved homogenization theory for the spiral corrugated FGM structure is applied and the geometrical nonlinearity in a von Karman sense is taken into account. The nonlinear equilibrium equation system can be solved by using the Galerkin method with the three-term solution form of deflection. An explicit solution form for the nonlinear buckling behavior of shells is obtained. The critical buckling pressure and the postbuckling strength of shells are numerically investigated. Additionally, the effects of spiral corrugation in enhancing the nonlinear buckling behavior of spiral corrugated sandwich FGM cylindrical shells are validated and discussed.

scholarly journals An analytical approach to analyze nonlinear dynamic response of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure. Part 2: Numerical results and discussion

2014 ◽  
Vol 36 (4) ◽  
pp. 255-265 ◽  
Author(s):  
Dao Van Dung ◽  
Vu Hoai Nam
Keyword(s):  
Axial Compression ◽  
Nonlinear Dynamic ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
External Pressure ◽  
Dynamic Buckling ◽  
Functionally Graded ◽  
Numerical Results ◽  
Time Dependent ◽  
Circular Cylindrical Shells

Based on the classical thin shell theory with the geometrical nonlinearity in von Karman-Donnell sense, the smeared stiffener technique, Galerkin method and an approximate three-term solution of deflection taking into account the nonlinear buckling shape is chosen, the governing nonlinear dynamic equations of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure is established in part 1. In this study, the nonlinear dynamic responses are obtained by fourth order Runge-Kutta method and the nonlinear dynamic buckling behavior of stiffened functionally graded shells under linear-time loading is determined by according to Budiansky-Roth criterion. Numerical results are investigated to reveal effects of stiffener, input factors on the vibration and nonlinear dynamic buckling loads of stiffened functionally graded circular cylindrical shells.

Nonlinear Stability of Sandwich Functionally Graded Cylindrical Shells with Stiffeners Under Axial Compression in Thermal Environment

2019 ◽  
Vol 19 (07) ◽  
pp. 1950073 ◽  
Author(s):  
Nguyen Thi Phuong ◽  
Vu Hoai Nam ◽  
Nguyen Thoi Trung ◽  
Vu Minh Duc ◽  
Pham Van Phong
Keyword(s):  
Thermal Stresses ◽  
Thermal Environment ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
Functionally Graded ◽  
Nonlinear Buckling ◽  
Buckling Behavior ◽  
Compressive Loads ◽  
Graded Material ◽  
Orthogonal Stiffeners

The geometrically nonlinear response of sandwich functionally graded cylindrical shells reinforced by orthogonal and/or spiral stiffeners and subjected to axial compressive loads is investigated in this paper. Two types of sandwich functionally graded material models are considered. The formulations are based on the Donnell shell theory considering geometrical nonlinearity and Pasternak’s elastic foundation. The improved Lekhnitskii’s smeared stiffener technique is used to account for the stiffener effects with both mechanical and thermal stresses. The results obtained indicate that the spiral stiffeners have significantly beneficial influences in comparison with orthogonal stiffeners on the nonlinear buckling behavior of shells. The relatively large effects of temperature change, geometrical and material parameters are also demonstrated in the numerical investigations.

scholarly journals Solving nonlinear stability problem of imperfect functionally graded circular cylindrical shells under axial compression by Galerkin's method

2012 ◽  
Vol 34 (3) ◽  
pp. 139-156 ◽  
Author(s):  
Dao Van Dung ◽  
Le Kha Hoa
Keyword(s):  
Axial Compression ◽  
Nonlinear Stability ◽  
Volume Fraction ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
Functionally Graded ◽  
Galerkin’S Method ◽  
Galerkin's Method ◽  
Method Effects ◽  
Circular Cylindrical Shells

This paper presents an analytical approach to analyze the nonlinear stability of thin closed circular cylindrical shells under axial compression with material properties varying smoothly along the thickness in the power and exponential distribution laws. Equilibrium and compatibility equations are obtained by using Donnel shell theory taking into account the geometrical nonlinearity in von Karman and initial geometrical imperfection.  Equations to find the critical load and the load-deflection curve are established by Galerkin's method. Effects of buckling modes, of imperfection, of dimensional parameters and of volume fraction indexes to buckling loads and postbuckling load-deflection curves of cylindrical shells are investigated. In case of perfect cylindrical shell, the present results coincide with the ones of the paper  [13] which were solved by Ritz energy method.

Nonlinear thermomechanical buckling of sandwich FGM oblique stiffened plates with nonlinear effect of elastic foundation

2020 ◽  
pp. 089270572093595
Author(s):  
Dang Thuy Dong ◽  
Vu Hoai Nam ◽  
Nguyen Thoi Trung ◽  
Nguyen Thi Phuong ◽  
Vu Tho Hung
Keyword(s):  
Elastic Foundation ◽  
Geometrical Nonlinearity ◽  
Shear Deformation Theory ◽  
Equation System ◽  
External Pressure ◽  
Functionally Graded ◽  
Geometrical Properties ◽  
Nonlinear Elastic Foundation ◽  
The Galerkin Method ◽  
Nonlinear Elastic

In this article, the nonlinear thermomechanical buckling behaviors of sandwich functionally graded plates subjected to an axial compression and external pressure are analytically analyzed resting on nonlinear elastic foundation. Assuming that the plates are reinforced by oblique stiffeners and rested on nonlinear elastic foundation. The formulations are established using the higher-order shear deformation theory taking into account the geometrical nonlinearity of von Kármán. The Lekhnitskii’s smeared stiffener technique is developed for shear deformable oblique stiffener system using the coordinate transformation technique with both mechanical and thermal terms. The Galerkin method is utilized to obtain the nonlinear algebraically equation system, then, solve it to determine the explicit expressions of critical buckling loads and postbuckling load–deflection curves. Numerical results show the effects of temperature, nonlinear elastic foundation, stiffeners, and material and geometrical properties on nonlinear behaviors of plates.

Nonlinear thermal vibration and dynamic buckling of eccentrically stiffened sandwich-FGM cylindrical shells containing fluid

2018 ◽  
Vol 38 (6) ◽  
pp. 253-266
Author(s):  
Khuc Van Phu ◽  
Dao Huy Bich ◽  
Le Xuan Doan
Keyword(s):  
Thermal Environment ◽  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
Fluid Pressure ◽  
Dynamic Buckling ◽  
Functionally Graded ◽  
Dynamic Responses ◽  
Thermal Vibration ◽  
Foundation Model ◽  
Classical Shell Theory

The governing equations for analysing thermal vibration and dynamic buckling of eccentrically stiffened sandwich functionally graded cylindrical shells full filled with fluid and surrounded by elastic foundations in thermal environment are derived by using the classical shell theory, the geometrical nonlinearity in von Karman-Donnell sense, the smeared stiffener technique and Pasternak’s foundation model. Solutions of the problem are established according to the Galerkin’s method and Runge–Kutta method. The effects of fluid pressure, stiffeners, geometrical ratios, temperature and elastic foundation on the dynamic responses of shells are investigated.

Nonlinear buckling of orthogonal carbon nanotube-reinforced composite cylindrical shells under axial compression surrounded by elastic foundation in thermal environment

2019 ◽  
Vol 08 (04) ◽  
pp. 1950016 ◽  
Author(s):  
Vu Hoai Nam ◽  
Nguyen Thi Phuong ◽  
Vu Minh Duc
Keyword(s):  
Carbon Nanotube ◽  
Elastic Foundation ◽  
Axial Compression ◽  
Volume Fraction ◽  
Thermal Environment ◽  
Cylindrical Shells ◽  
Geometrical Parameters ◽  
Postbuckling Behavior ◽  
Nonlinear Buckling ◽  
Reinforced Composite

Nonlinear buckling and postbuckling of orthogonal carbon nanotube-reinforced composite (Orthogonal CNTRC) cylindrical shells subjected to axial compression in thermal environments surrounded by elastic foundation are presented in this paper. Two layers of shell are reinforced by carbon nanotube (CNT) in two orthogonal directions (longitudinal and circumferential directions). Based on Donnell’s shell theory with von Karman’s nonlinearity and the Galerkin method, the governing equations are established to obtain the critical buckling loads and postbuckling load-deflection curves. The large effects of CNT volume fraction, temperature change, elastic foundation and geometrical parameters of cylindrical shells on the buckling load and postbuckling behavior of Orthogonal CNTRC cylindrical shells are obtained.

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