Power Law of Critical Buckling in Structural Members Supported by a Winkler Foundation

2016 ◽  
Vol 33 (3) ◽  
pp. 369-374
Author(s):  
M. Sato ◽  
S. Harasawa ◽  
Y. Konishi ◽  
T. Maruyama ◽  
S. J. Park
Keyword(s):  
Elastic Medium ◽  
Power Law ◽  
Axial Loading ◽  
Elastic Buckling ◽  
Winkler Foundation ◽  
Structural Members ◽  
Spherical Shells ◽  
Buckling Modes ◽  
Plates And Shells ◽  
Critical Buckling Strain

AbstractIn the fields of engineering, nanoscience, and biomechanics, thin structural members, such as beams, plates, and shells, that are supported by an elastic medium are used in several applications. There is a possibility that these thin structures might buckle under severe loading conditions; higher-order, complicated elastic buckling modes can be found owing to the balance of rigidities between the thin members and elastic supports. In this study, we have shown a new and simple ‘power law’ relation between the critical buckling strain (or loads) and rigidity parameters in structural members supported by an elastic medium, which can be modelled as a Winkler foundation. The following structural members have been considered in this paper: i) a slender beam held by an outer elastic support under axial loading, ii) cylindrical shells supported by an inner elastic core under hydrostatic pressure (plane strain condition), and iii) complete spherical shells that are filled with an inner elastic medium.

scholarly journals Hydrostatically pressurized buckling of complete spherical shells filled with an elastic medium

2011 ◽  
Vol 67 (2) ◽  
pp. I_15-I_22
Author(s):  
Motohiro SATO ◽  
M. Ahmer WADEE ◽  
Takafumi SEKIZAWA ◽  
Kohtaroh IIBOSHI ◽  
Hiroyuki SHIMA
Keyword(s):  
Elastic Medium ◽  
Spherical Shells

Elastic Follow-Up Factor for Cruciform Plate Under Bi-Axial Loading

2011 ◽  
Author(s):  
Kuk-Hee Lee ◽  
Yun-Jae Kim ◽  
Robert A. Ainsworth ◽  
David Dean ◽  
Tae-Eun Jin
Keyword(s):  
Finite Element ◽  
Power Law ◽  
Analytical Solutions ◽  
Axial Stress ◽  
Axial Loading ◽  
Finite Element Analyses ◽  
Structural Discontinuity ◽  
Stress States ◽  
Power Law Creep

This paper derives analytical solutions of the elastic follow-up factor for power-law creeping cruciform plates under bi-axial displacements to investigate the effect of multi-axial stress states on elastic follow-up behaviors. Validity of the proposed solutions is checked against the results from finite element analyses using power-law creep material. Based on proposed solutions, effects of the biaxiality, geometry, Poisson’s ratio and creep exponent on elastic follow-up factors are discussed. Present results show that the elastic follow-up factor for structure with structural discontinuity can be significantly affected by the multi-axial stress states.

Buckling of Fibre-Reinforced Plastic-Steel Torispherical Shells Under External Pressure

1988 ◽  
Vol 202 (6) ◽  
pp. 409-420 ◽  
Author(s):  
G D Galletly ◽  
A Muc
Keyword(s):  
External Pressure ◽  
Experimental Results ◽  
Steel Shell ◽  
Elastic Buckling ◽  
Geometrical Parameters ◽  
Initial Shape ◽  
Buckling Modes ◽  
Reinforced Plastic ◽  
Composite Layers ◽  
Spherical Caps

The paper deals with the buckling of torispherical shells consisting of a steel external layer plus different numbers of composite layers. It is assumed that the total thickness of the fibre-reinforced plastic (FRP)-steel shell is constant but that the thickness of the steel and of the composite may be varied. In the paper it is shown (a) how the orientation of the fibres and the composite lamina thicknesses affect the elastic buckling modes and (b) how substantial increases in elastic buckling pressures may be achieved by reinforcing the steel torispheres with layers of composite. The analysis is carried out for various values of the geometrical parameters describing torispheres, including spherical caps. The influence of the yielding of the steel layer on the buckling pressures of FRP-steel torispheres is also discussed. As might be expected, it is necessary to take plasticity into account when predicting the buckling pressures of these shells. Some experimental results are given which confirm this expectation. The effect of initial shape imperfections in the shells is also considered briefly. However, the dearth of experimental results on FRP-steel shells prevents a proper evaluation of the way in which imperfections decrease their buckling strength.

Dent Imperfections in Shell Buckling: The Role of Geometry, Residual Stress, and Plasticity

2020 ◽  
Vol 88 (3) ◽  
Author(s):  
S. Gerasimidis ◽  
J. W. Hutchinson
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Middle Surface ◽  
External Pressure ◽  
Second Step ◽  
Elastic Buckling ◽  
Spherical Shells ◽  
Shell Buckling ◽  
Cylindrical Metal

Abstract Departures of the geometry of the middle surface of a thin shell from the perfect shape have long been regarded as the most deleterious imperfections responsible for reducing a shell’s buckling capacity. Here, systematic simulations are conducted for both spherical and cylindrical metal shells whereby, in the first step, dimple-shaped dents are created by indenting a perfect shell into the plastic range. Then, in the second step, buckling of the dented shell is analyzed, under external pressure for the spherical shells and in axial compression for the cylindrical shells. Three distinct buckling analyses are carried out: (1) elastic buckling accounting only for the geometry of the dent, (2) elastic buckling accounting for both dent geometry and residual stresses, and (3) a full elastic–plastic buckling analysis accounting for both the dent geometry and residual stresses. The analyses reveal the relative importance of the geometry and the residual stress associated with the dent, and they also provide a clear indicator of whether plasticity is important in establishing the buckling load of the dented shells.

Effect of Discrete Sectional Bonding of Cellular Core on Impact Performance of Square Tubes: A Finite Element Study

2018 ◽  
Author(s):  
Muhammad Ali ◽  
Eboreime Ohioma ◽  
Khairul Alam
Keyword(s):  
Impact Loading ◽  
Axial Loading ◽  
Deformation Mode ◽  
Displacement Curve ◽  
Structural Members ◽  
Progressive Deformation ◽  
Impact Performance ◽  
Deformation Modes ◽  
Force Displacement ◽  
Passenger Cabin

Thin walled members such as square tubes are commonly used in vehicle’s frontal chassis to provide protection and damage attenuation to the passenger cabin in the case of impact loading. These structural members undergo progressive deformation under axial loading. The type of deformation mode is critical as it defines the overall configuration of force-displacement curve. There are different types of deformation modes for square tube under axial loading. Likewise, cellular structure exhibit distinct deformation modes under in-plane loading. The work presented here investigates the effects of partial or discrete bonding of cellular core structure on deformation modes of square tubes under axial loading. The results show that discrete bonding of cellular core with the tube has significant effect on progressive deformation of tubes and therefore, presents an opportunity to re-configure force-displacement curve for improved protection of automobile structures under impact loading.

Simulation of Cold-Formed Steel Beams in Global and Distortional Buckling

2014 ◽  
Vol 633-634 ◽  
pp. 1037-1041 ◽  
Author(s):  
Nikolay Vatin ◽  
Aleksei Sinelnikov ◽  
Marsel Garifullin ◽  
Darya Trubina
Keyword(s):  
Fe Simulation ◽  
Critical Force ◽  
Steel Beams ◽  
Elastic Buckling ◽  
Distortional Buckling ◽  
Pure Bending ◽  
Buckling Modes ◽  
New Type ◽  
Cold Formed Steel ◽  
Computing Simulation

This article provides the numerical elastic buckling analysis of simply supported cold-formed lipped channels subjected to pure bending. A methodology for computing simulation of a new type of thin-walled thermo-profile (reticular-stretched) is developed. For flexural elements buckling modes and values of critical force are calculated. FE simulation evaluates the influence of web height and span on the critical load and buckling modes for cold formed beams of different lengths.

scholarly journals Strongly Localized Image States of Spherical Graphitic Particles

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Godfrey Gumbs ◽  
Antonios Balassis ◽  
Andrii Iurov ◽  
Paula Fekete
Keyword(s):  
Power Law ◽  
Effective Potential ◽  
Charged Particles ◽  
Angular Motion ◽  
Centripetal Force ◽  
Spherical Image ◽  
Spherical Shells ◽  
Surface Potentials ◽  
Image States

We investigate the localization of charged particles by the image potential of spherical shells, such as fullerene buckyballs. These spherical image states exist within surface potentials formed by the competition between the attractive image potential and the repulsive centripetal force arising from the angular motion. The image potential has a power law rather than a logarithmic behavior. This leads to fundamental differences in the nature of the effective potential for the two geometries. Our calculations have shown that the captured charge is more strongly localized closest to the surface for fullerenes than for cylindrical nanotube.

Elastic Critical Buckling Modes and Stress of Cold-Formed Thin-Walled Lipped Channel with Multiple Intermediate Stiffeners

2014 ◽  
Vol 501-504 ◽  
pp. 470-473
Author(s):  
Guang Yue Ma
Keyword(s):  
Theoretical Analysis ◽  
Experimental Results ◽  
Elastic Buckling ◽  
Channel Member ◽  
Buckling Modes ◽  
Important Thing ◽  
Buckling Stress ◽  
Thin Walled

Elastic buckling modes of cold-formed thin-walled steel member have three relevant types: local, distortional and global. The complicated and important thing is to differentiating buckling modes and resolving buckling stress for engineers. It will be given for Cold-formed thin-walled lipped channel member with multiple intermediate stiffeners. The theoretical analysis coincide exactly with the experimental results, it can be used as a reference for engineers.

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