Effect of geometrical parameters on mode shape and critical buckling load of dished shells under external pressure

2016 ◽  
Vol 106 ◽  
pp. 218-227 ◽  
Author(s):  
Surya Mani Tripathi ◽  
Anup S ◽  
R. Muthukumar
Keyword(s):  
Mode Shape ◽  
External Pressure ◽  
Buckling Load ◽  
Geometrical Parameters ◽  
Critical Buckling Load

Buckling of 2D-FG Cylindrical Shells under Combined External Pressure and Axial Compression

2013 ◽  
Vol 5 (03) ◽  
pp. 391-406 ◽  
Author(s):  
R. Mohammadzadeh ◽  
M. M. Najafizadeh ◽  
M. Nejati
Keyword(s):  
Cylindrical Shell ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
Axial Direction ◽  
External Pressure ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Classical Shell Theory ◽  
The Stability

AbstractThis paper presents the stability of two-dimensional functionally graded (2D-FG) cylindrical shells subjected to combined external pressure and axial compression loads, based on classical shell theory. The material properties of functionally graded cylindrical shell are graded in two directional (radial and axial) and determined by the rule of mixture. The Euler’s equation is employed to derive the stability equations, which are solved by GDQ method to obtain the critical mechanical buckling loads of the 2D-FG cylindrical shells. The effects of shell geometry, the mechanical properties distribution in radial and axial direction on the critical buckling load are studied and compared with a cylindrical shell made of 1D-FGM. The numerical results reveal that the 2D-FGM has a significant effect on the critical buckling load.

Fourier Series Analysis of Cylindrical Pressure Vessel Subjected to External Pressure

2009 ◽  
Author(s):  
Gurinder Singh Brar ◽  
Yogeshwar Hari ◽  
Dennis K. Williams
Keyword(s):  
Fourier Series ◽  
Pressure Vessel ◽  
Large Diameter ◽  
External Pressure ◽  
Pressure Vessels ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Cylindrical Pressure Vessel ◽  
Section Viii ◽  
Division 2

This paper presents the comparison of a reliability technique that employs a Fourier series representation of random asymmetric imperfections in a cylindrical pressure vessel subjected to external pressure. Comparison with evaluations prescribed by the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 Rules for the same shell geometries are also conducted. The ultimate goal of the reliability type technique is to predict the critical buckling load associated with the chosen cylindrical pressure vessel. Initial geometric imperfections are shown to have a significant effect on the load carrying capacity of the example cylindrical pressure vessel. Fourier decomposition is employed to interpret imperfections as structural features that can be easily related to various other types of defined imperfections. The initial functional description of the imperfections consists of an axisymmetric portion and a deviant portion, which are availed in the form of a double Fourier series. Fifty simulated shells generated by the Monte Carlo technique are employed in the final prediction of the critical buckling load. The representation of initial geometrical imperfections in the cylindrical pressure vessel requires the determination of appropriate Fourier coefficients. Multi-mode analyses are expanded to evaluate a large number of potential buckling modes for both predefined geometries and associated asymmetric imperfections as a function of position within a given cylindrical shell. The probability of the ultimate buckling stress that may exceed a predefined threshold stress is also calculated. The method and results described herein are in stark contrast to the “knockdown factor” approach as applied to compressive stress evaluations currently utilized in industry. Recommendations for further study of imperfect cylindrical pressure vessels are also outlined in an effort to improve on the current design rules regarding column buckling of large diameter pressure vessels designed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 2 and ASME STS-1.

scholarly journals A semi-analytical model on the critical buckling load of perforated plates with opposite free edges

2022 ◽  
pp. 095440622110568
Author(s):  
Weigang Fu ◽  
Bin Wang
Keyword(s):  
Analytical Model ◽  
Perforated Plate ◽  
Beam Theory ◽  
Buckling Load ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Engineering Structures ◽  
Perforated Plates ◽  
Critical Buckling Load ◽  
Free Edges

Perforated plates are widely used in thin-walled engineering structures, for example, for lightweight designs of structures and access for installation. For the purpose of analysis, such perforated plates with two opposite free edges might be considered as a series of successive Timoshenko beams. A new semi-analytical model was developed in this study using the Timoshenko shear beam theory for the critical buckling load of perforated plates, with the characteristic equations derived. Results of the proposed modelling were compared with those obtained by FEM and show good agreement. The influence of the dividing number of the successive beams on the accuracy of the critical buckling load was studied with respect to various boundary conditions. And the effect of geometrical parameters, such as the aspect ratio, the thickness-to-width ratio and the cutout-to-width ratio were also investigated. The study shows that the proposed semi-analytical model can be used for buckling analysis of a perforated plate with opposite free edges with the capacity to consider the shear effect in thick plates.

Dynamic Buckling of Cylindrical Shells with Arbitrary Axisymmetric Thickness Variation under Time Dependent External Pressure

2015 ◽  
Vol 15 (03) ◽  
pp. 1450053 ◽  
Author(s):  
Hai-Gui Fan ◽  
Zhi-Ping Chen ◽  
Wen-Zhuo Feng ◽  
Fan Zhou ◽  
Guo-Wei Cao
Keyword(s):  
Cylindrical Shells ◽  
External Pressure ◽  
Dynamic Buckling ◽  
Buckling Load ◽  
Fourier Series Expansion ◽  
Thickness Variation ◽  
Critical Buckling Load ◽  
Critical Dynamic ◽  
Variation Parameter ◽  
Analytical Formulas

This paper presents an analytical study on the critical dynamic buckling load of cylindrical shells with arbitrary axisymmetric thickness variation under uniform external pressure which is a function of time. Based on the Donnell simplified principle, the equilibrium and compatibility equations of cylindrical shells with arbitrary axisymmetric wall thickness under dynamic external pressure were derived. By using the method of separation of variables, the equations were transformed into ordinary differential equations in nondimensional form. Combining Fourier series expansion and the regular perturbation method, as well as the Sachenkov–Baktieva method, analytical formulas of the critical buckling load of cylindrical shells with arbitrary axisymmetric thickness variation under dynamic external pressure that varies as a power function of time were obtained. Using these analytical formulas, the critical dynamic buckling load of cylindrical shells with linearly and parbolically varying thickness were computed. The influences of thickness variation parameter and loading speed of external pressure on the critical buckling load were also discussed. The method was also applied to cylindrical shells with a classical cosine form thickness variation, by introducing the reduction factor of critical dynamic buckling load. The buckling capacity of these cylindrical shells under dynamic external pressure was discussed considering the effects of loading speed and thickness variation parameter.

Designing pinhole vacancies in graphene towards functionalization: Effects on critical buckling load

2017 ◽  
Vol 103 ◽  
pp. 343-357 ◽  
Author(s):  
S.K. Georgantzinos ◽  
S. Markolefas ◽  
G.I. Giannopoulos ◽  
D.E. Katsareas ◽  
N.K. Anifantis
Keyword(s):  
Buckling Load ◽  
Critical Buckling Load

scholarly journals Nonlocal vibration and buckling of two-dimensional layered quasicrystal nanoplates embedded in an elastic medium

2021 ◽  
Author(s):  
Tuoya Sun ◽  
Junhong Guo ◽  
E. Pan
Keyword(s):  
Elastic Medium ◽  
Vibration Frequency ◽  
Surrounding Medium ◽  
Nonlocal Parameter ◽  
Buckling Load ◽  
Width Ratio ◽  
Two Dimensional ◽  
Coating Materials ◽  
Decagonal Quasicrystal ◽  
Critical Buckling Load

AbstractA mathematical model for nonlocal vibration and buckling of embedded two-dimensional (2D) decagonal quasicrystal (QC) layered nanoplates is proposed. The Pasternak-type foundation is used to simulate the interaction between the nanoplates and the elastic medium. The exact solutions of the nonlocal vibration frequency and buckling critical load of the 2D decagonal QC layered nanoplates are obtained by solving the eigensystem and using the propagator matrix method. The present three-dimensional (3D) exact solution can predict correctly the nature frequencies and critical loads of the nanoplates as compared with previous thin-plate and medium-thick-plate theories. Numerical examples are provided to display the effects of the quasiperiodic direction, length-to-width ratio, thickness of the nanoplates, nonlocal parameter, stacking sequence, and medium elasticity on the vibration frequency and critical buckling load of the 2D decagonal QC nanoplates. The results show that the effects of the quasiperiodic direction on the vibration frequency and critical buckling load depend on the length-to-width ratio of the nanoplates. The thickness of the nanoplate and the elasticity of the surrounding medium can be adjusted for optimal frequency and critical buckling load of the nanoplate. This feature is useful since the frequency and critical buckling load of the 2D decagonal QCs as coating materials of plate structures can now be tuned as one desire.

Effect of Fiber Orientation on the Critical Buckling Load of Symmetric Composite Laminated Plates

2012 ◽  
Vol 629 ◽  
pp. 95-99 ◽  
Author(s):  
N. Hamani ◽  
D. Ouinas ◽  
N. Taghezout ◽  
M. Sahnoun ◽  
J. Viña
Keyword(s):  
Fiber Orientation ◽  
Composite Plates ◽  
Laminated Plates ◽  
Buckling Load ◽  
The Finite Element Method ◽  
Notch Radius ◽  
Critical Buckling Load ◽  
Buckling Strength ◽  
Degree Of Anisotropy ◽  
Circular Notch

In this study, a buckling analysis is performed on rectangular composite plates with single and double circular notch using the finite element method. Laminated plates of carbon/bismaleimde (IM7/5250-4) are ordered symmetrically as follows [(θ/-θ)2]S. The buckling strength of symmetric laminated plates subjected to uniaxial compression is highlighted as a function of the fibers orientations. The results show that whatever the notch radius, the buckling load is almost stable. Increasing the degree of anisotropy significantly improves critical buckling load.

Deformation of Perforated Aluminium Plates under In-Plane Compressive Loading

2016 ◽  
Vol 710 ◽  
pp. 357-362
Author(s):  
Irene Scheperboer ◽  
Evangelos Efthymiou ◽  
Johan Maljaars
Keyword(s):  
Research Work ◽  
Compressive Loading ◽  
Local Buckling ◽  
Buckling Load ◽  
Structural Behaviour ◽  
Critical Buckling Load ◽  
Out Of Plane ◽  
The Difference ◽  
Ultimate Resistance ◽  
Multiple Holes

Aluminium plates containing a single hole or multiple holes in a row are recently becoming very popular among architects and consultant engineers in many constructional applications, due to their reduced weight, as well as facilitating ventilation and light penetration of the buildings. However, there are still uncertainties concerning their structural behaviour, preventing them from wider utilization. In the present paper, local buckling phenomenon of perforated aluminium plates has been studied using the finite element method. For the purposes of the research work, plates with simply supported edges in the out-of-plane direction and subjected to uniaxial compression are examined. In view of perforations, circular cut-outs and the total cut-out size has been varied between 5 and 40% of the total plate area. Moreover, different perforation patterns have been investigated, from a single, central cut-out to a more refined pattern consisting of up to 25 holes equally distributed over the plate. Regarding the material characteristics, several aluminium alloys are considered and compared to steel grade A36 on plates of different slenderness. For each case the critical (Euler) buckling load and the ultimate resistance has been determined.A study into the boundary conditions of the plate showed that the restrictions at the edges parallel to the load direction have a large influence on the critical buckling load. Restraining the top or bottom edge does not significantly influence the resistance of the plate.The results showed that the ultimate resistance of aluminium plates containing multiple holes occurs at considerably larger out-of-plane displacement as that of full plates. For very large total cut-out, a plate containing a central hole has a larger resistance than a plate with equal cut-out percentage but with multiple holes. The strength and deformation in the post-critical regime, i.e. the difference between the critical buckling load and the ultimate resistance, differs significantly for different number of holes and cut-out percentage.

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