On the bifurcation buckling and vibration of porous nanobeams

2020 ◽  
Vol 250 ◽  
pp. 112632 ◽  
Author(s):  
Piotr Jankowski ◽  
Krzysztof Kamil Żur ◽  
Jinseok Kim ◽  
J.N. Reddy
Keyword(s):  
Bifurcation Buckling

Clamped torispherical shells under external pressure — some new results

1988 ◽  
Vol 23 (1) ◽  
pp. 9-24 ◽  
Author(s):  
J Blachut ◽  
G D Galletly
Keyword(s):  
Failure Mode ◽  
External Pressure ◽  
Spherical Cap ◽  
Geometric Imperfections ◽  
Collapse Pressure ◽  
Modes Of Failure ◽  
Shell Buckling ◽  
Bifurcation Buckling ◽  
Initial Geometric Imperfections ◽  
The One

Perfect clamped torispherical shells subjected to external pressure are analysed in the paper using the BOSOR 5 shell buckling program. Various values of the knuckle radius-to-diameter ratio ( r/D) and the spherical cap radius-to-thickness ratio ( Rs/ t) were studied, as well as four values of σyp, the yield point of the material. Buckling/collapse pressures, modes of failure and the development of plastic zones in the shell wall were determined. A simple diagram is presented which enables the failure mode in these shells to be predicted. The collapse pressures, pc, were also plotted against the parameter Λs (√( pyp/ pcr)). When the controlling failure mode was axisymmetric yielding in the knuckle, the collapse pressure curves depended on the value of σyp, which is unusual. However, when the controlling failure mode was bifurcation buckling (at the crown/knuckle junction), the collapse pressure curves for the various values of σyp all merged, i.e., they were independent of σyp. This latter situation is the one which normally occurs with the buckling of cylindrical and hemispherical shells. A limited investigation was also made into the effects of axisymmetric initial geometric imperfections on the strength of externally-pressurised torispherical shells. When the failure mode was axisymmetric yielding in the knuckle, initial imperfections of moderate size did not affect the collapse pressures. In the cases where bifurcation buckling at the crown/knuckle junction occurred, small initial geometric imperfections at the apex did not affect the buckling pressure, but axisymmetric imperfections at the buckle location did influence it. With the other failure mode (i.e., axisymmetric yielding collapse at the crown of the shell), initial geometric imperfections caused a reduction in the torisphere's strength.

Bifurcation buckling from a membrane stress state

2012 ◽  
Vol 90 (7) ◽  
pp. 867-881 ◽  
Author(s):  
Herbert A. Mang ◽  
Gerhard Höfinger
Keyword(s):  
Stress State ◽  
Membrane Stress ◽  
Bifurcation Buckling

Nondimensional Parameters and Equations for Buckling of Anisotropic Shallow Shells

1994 ◽  
Vol 61 (3) ◽  
pp. 664-669 ◽  
Author(s):  
M. P. Nemeth
Keyword(s):  
Laminated Shells ◽  
Shallow Shells ◽  
Fundamental Parameters ◽  
Combined Loads ◽  
Vlasov Equations ◽  
Shell Buckling ◽  
Bifurcation Buckling ◽  
Z Parameter ◽  
Shear Buckling ◽  
Doubly Curved

A procedure for deriving nondimensional parameters and equations for bifurcation buckling of anisotropic shallow shells subjected to combined loads is presented. First, the Donnell-Mushtari-Vlasov equations governing buckling of symmetrically laminated doubly curved thin elastic shallow shells are presented. Then, the rationale used to perform the nondimensionalization of the buckling equations is presented, and fundamental parameters are identified that represent measures of the shell orthotropy and anisotropy. In addition, nondimensional curvature parameters are identified that are analogues of the well-known Batdorf Z parameter for isotropic shells, and analogues of Dunnell’s and Batdorf s shell buckling equations are presented. Selected results are presented for shear buckling of balanced symmetric laminated shells that illustrate the usefulness of the nondimensional parameters.

Buckling Analysis of Sandwich Shell Structures Subjected to Hydrostatic Load

1994 ◽  
Vol 31 (02) ◽  
pp. 106-115
Author(s):  
C. Chryssostomidis ◽  
N.A. Papadakis
Keyword(s):  
Sandwich Structure ◽  
Critical Pressure ◽  
Thickness Distribution ◽  
Global Bifurcation ◽  
Local Buckling ◽  
Shell Structures ◽  
The Core ◽  
Bifurcation Buckling ◽  
Hydrostatic Load ◽  
Global Buckling

This paper examines the buckling phenomenon of sandwich cylindrical shell structures subjected to hydrostatic pressure. Global bifurcation buckling is considered, and the effect of discrete ring stiffeners on the critical pressure is analyzed. The local buckling problem is discussed, including the influence of the shape and the thickness of the core stiffeners on the critical load. Finally, the paper treats the sensitivity of local and global buckling on the thickness distribution between the inner and outer shells of the sandwich structure.

Bifurcation Buckling

2020 ◽  
pp. 169-169
Keyword(s):  
Bifurcation Buckling

Numerical analysis of bifurcation buckling for rotationally periodic structures under rotationally periodic loads

1998 ◽  
Vol 14 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Li Jianzhong ◽  
Liu Yinghua ◽  
Cen Zhangzhi ◽  
Xu Bingye
Keyword(s):  
Numerical Analysis ◽  
Periodic Structures ◽  
Bifurcation Buckling

scholarly journals Strength determination for band-loaded thin cylinders

2018 ◽  
Vol 21 (16) ◽  
pp. 2454-2465
Author(s):  
Cornelia Doerich ◽  
Margi Vilnay ◽  
J Michael Rotter
Keyword(s):  
Cylindrical Shells ◽  
Plastic Collapse ◽  
European Standard ◽  
Line Load ◽  
Finite Height ◽  
Bifurcation Buckling ◽  
Strength Determination

Cylindrical shells are often subjected to local inward loads normal to the shell that arise over restricted zones. A simple axisymmetric example is that of the ring-loaded cylinder, in which an inward line load around the circumference causes either plasticity or buckling. The ring-loaded cylinder problem is highly relevant to shell junctions in silos, tanks and similar assemblies of shell segments. The band load is similar to the ring load in which a band of inward axisymmetric pressure is applied over a finite height. When the height is very small, the situation approaches the ring-loaded case, and when the height is very large, it approaches the uniformly pressurised case. This article first thoroughly explores the two limiting cases of plastic collapse and linear bifurcation buckling, which must both be fully defined before a complete description of the nonlinear and imperfection-sensitive strengths of such shells can be described within the framework of the European standard for shells (EN 1993-1-6). Finally, the application of the reference resistance design (RRD) over the complete range of geometries for the perfect structure is shown using the outcome of the limiting cases.

ON STATIC STABILITY OF NONLINEARLY ELASTIC EULER'S COLUMNS OBEYING THE MODIFIED LUDWICK'S LAW

2012 ◽  
Vol 12 (06) ◽  
pp. 1250077 ◽  
Author(s):  
MIHA BROJAN ◽  
MATEJ SITAR ◽  
FRANC KOSEL
Keyword(s):  
Constitutive Model ◽  
Static Stability ◽  
Engineering Practice ◽  
Structural Systems ◽  
Structural Elements ◽  
Material Parameters ◽  
Bifurcation Buckling ◽  
Elastic Column ◽  
The Stability ◽  
Nonlinearly Elastic

It is illustrated in this paper that a nonlinearly elastic column, depending upon the values of different material parameters involved, exhibits several stability characteristics and types of buckling which are generally observed separately in distinctively different structural systems. By introducing finite disturbances it is shown that the column may buckle well before the bifurcation buckling load is reached. The proposed approach can be useful in engineering practice since it can be utilized to study the stability of uniaxial structural elements made from rubber or any other material which obeys the modified Ludwick's constitutive model.

scholarly journals Similarity consideration of structural bifurcation buckling

1999 ◽  
Vol 65 (4) ◽  
pp. 107-112 ◽  
Author(s):  
Y. P. Zhao
Keyword(s):  
Bifurcation Buckling ◽  
Structural Bifurcation
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