Buckling of Simply Supported Plates Tapered in Planform

1956 ◽  
Vol 23 (2) ◽  
pp. 207-213
Author(s):  
Bertram Klein
Keyword(s):  
Elastic Buckling ◽  
Axial Loads ◽  
Flat Plates ◽  
Buckling Loads ◽  
Simply Supported ◽  
Shear Loads ◽  
Limiting Case ◽  
The Given

Abstract Design curves are presented for determining the elastic buckling loads of simply supported flat plates of isosceles trapezoidal planform and loaded in compression along the parallel edges. Shear loads are assumed to act along the sloping edges so that any ratio of axial loads may act along the parallel edges of the given plate. Isosceles triangular plates are included as a special limiting case, and the range of the values of the various geometric and load parameters presented in the curves is considered large enough to cover practically all conditions of the type treated which are encountered in practice.

Elastic Buckling of Infinitely Long Trapezoidally Corrugated Plates in Shear

1978 ◽  
Vol 45 (3) ◽  
pp. 579-582 ◽  
Author(s):  
D. Perel ◽  
C. Libove
Keyword(s):  
Flat Plate ◽  
Energy Method ◽  
Orthotropic Plate ◽  
Plate Theory ◽  
Elastic Buckling ◽  
Flat Plates ◽  
Buckling Loads ◽  
Plate Elements ◽  
Corrugated Plates

Buckling loads are calculated for a class of infinitely long trapezoidally corrugated plates under uniform in-plane edge shear. This class consists of corrugated plates in which all interior plate elements are of equal width, with the end elements clamped. The energy method is used as the basis of analysis, which considers the corrugated plate as a nonplanar assemblage of flat plates. Buckling loads calculated using this method are compared to those obtained by using orthotropic plate theory, which represents the corrugated plate by an orthotropic flat plate. The comparison shows significant differences in predicted buckling loads.

The Bending, Buckling, and Flexural Vibration of Simply Supported Polygonal Plates by Point-Matching

1961 ◽  
Vol 28 (2) ◽  
pp. 288-291 ◽  
Author(s):  
H. D. Conway
Keyword(s):  
Hydrostatic Pressure ◽  
Boundary Conditions ◽  
Flexural Vibration ◽  
Frequency Equation ◽  
Numerical Results ◽  
Special Technique ◽  
Point Matching ◽  
Buckling Loads ◽  
Simply Supported ◽  
Flexural Vibrations

The bending by uniform lateral loading, buckling by two-dimensional hydrostatic pressure, and the flexural vibrations of simply supported polygonal plates are investigated. The method of meeting the boundary conditions at discrete points, together with the Marcus membrane analog [1], is found to be very advantageous. Numerical examples include the calculation of the deflections and moments, and buckling loads of triangular square, and hexagonal plates. A special technique is then given, whereby the boundary conditions are exactly satisfied along one edge, and an example of the buckling of an isosceles, right-angled triangle plate is analyzed. Finally, the frequency equation for the flexural vibrations of simply supported polygonal plates is shown to be the same as that for buckling under hydrostatic pressure, and numerical results can be written by analogy. All numerical results agree well with the exact solutions, where the latter are known.

scholarly journals Investigation of natural frequencies of axially loaded thin-walled columns

2018 ◽  
Vol 219 ◽  
pp. 02018
Author(s):  
Łukasz Żmuda-Trzebiatowski
Keyword(s):  
Applied Load ◽  
Natural Frequencies ◽  
Elastic Buckling ◽  
Correlation Technique ◽  
Buckling Loads ◽  
Perfectly Plastic ◽  
Linear Buckling ◽  
Thin Walled ◽  
Elastic Perfectly Plastic ◽  
Flexural Torsional Buckling

The paper deals with correlation between natural frequencies of two steel thin-walled columns and the corresponding applied load. The structures are made of cold-formed lipped channel sections. The columns lengths were assumed to follow two buckling patterns – global flexural and flexural-torsional buckling. In the thicker structure two material models were considered – linearly-elastic and elastic-perfectly plastic. Numerical computations cover dynamic eigenvalue problem, linear buckling and geometrically (and materially) non-linear analysis. The correlation between squares of natural frequencies and the applied load is linear in both columns. The first natural frequencies drop to zero due to structural buckling. This method, called the Vibration Correlation Technique, allows to predict buckling loads on the basis of measured vibration frequencies of the structures. Plasticity does not affect the corresponding curves – the use of the presented technique is limited to the structures exhibiting elastic buckling behaviour.

scholarly journals Effect of combination of pectin substances on viscosity of their aqueous solutions

2019 ◽  
Vol 81 (2) ◽  
pp. 133-138
Author(s):  
Z. N. Khatko ◽  
S. A. Titov ◽  
A. A. Ashinova ◽  
E. M. Kolodina
Keyword(s):  
Internal Friction ◽  
Aqueous Solutions ◽  
Dynamic Viscosity ◽  
Food Systems ◽  
Large Molecules ◽  
Related Substances ◽  
Shear Loads ◽  
Different Types ◽  
The Given ◽  
Pectin Substances

Viscosity is one of the characteristic properties of pectin substances, as well as other lyophilic colloids. Pectin molecules are easily associated with each other or with large molecules of related substances. This article contains the results of the study of dynamic viscosity, internal friction, thixotropic index of aqueous solutions (1 % and 4%) of various types of pectin substances and their combinations. The article presents the results of the study of the influence of different types of pectin substances and their combinations on the dynamic viscosity of pectin solutions and their internal friction. The analysis of values of dynamic viscosity and friction force depending on the type of pectin substances and their combinations is given. It is established that in cases where information on dissipative processes in pectin structures at low speeds and shear loads is required, it is necessary to rely on data on internal friction, in others - on the given information on their viscosity. The thixotropic index is calculated. It is established that the internal friction in pectin solutions and their dynamic viscosity depend on the type of pectin substances and their combinations. In pectin solutions, the internal friction is maximum for Apple pectin, and the dynamic viscosity – for a combination of citrus pectins with beet. When combining pectins, both indicators are most important for the combination of citrus with beet. The obtained data on the viscosity, internal friction and thixotropic index of solutions of different types and combinations of pectins make it possible to regulate the rheological properties of food systems with the addition of pectin substances.

The Behavior of a Poroelastic Seabed Under Normal and Shear Loads

1989 ◽  
Vol 111 (4) ◽  
pp. 303-310
Author(s):  
G. C. W. Sabin
Keyword(s):  
Normal Stress ◽  
Normal Load ◽  
Extended Period ◽  
Offshore Structures ◽  
Theoretical Discussion ◽  
Shear Loads ◽  
Pore Pressure Response ◽  
Limiting Case ◽  
Poroelastic Seabed ◽  
Parameters Of Interest

One of the effects of ice and water forces on large offshore structures which rest on the seabed is to transmit surface tractions to the region of contact. A recent paper by Sabin and Raman-Nair [1] has examined the effect of a normal axisymmetric load P(r, t) on a poroelastic seabed under several different conditions of boundary permeabilities. That study provided a number of general formulas for an arbitrary normal load. The present paper extends the results found in [1] to include shear tractions. While reference [1] was primarily a theoretical discussion, the present paper examines several specific forms of loading and presents graphs showing the normal stress and pore pressure response for various values of the parameters of interest. These results are compared with the limiting case of an extended period of time.

On the Buckling of Certain Optimum Plate Structures with Linearly Varying Thickness

1959 ◽  
Vol 10 (2) ◽  
pp. 145-148 ◽  
Author(s):  
E. H. Mansfield
Keyword(s):  
Local Buckling ◽  
Constant Thickness ◽  
Sectional Area ◽  
Longitudinal Compression ◽  
Cross Sectional ◽  
Plate Structures ◽  
Buckling Loads ◽  
Simply Supported ◽  
Euler Buckling ◽  
Varying Thickness

SummaryThis paper is concerned with the buckling under uniform longitudinal compression of a variety of structures composed of plates whose thickness tapers linearly to zero across the section. Such structures include the angle of Fig. 1, the strut of cruciform section of Fig. 2 and the simply-supported strip of Fig. 3. For given cross-sectional area and overall dimensions (e.g. length of arm) the sections with linearly varying thickness achieve a greater buckling load (assuming that local buckling, rather than Euler buckling, is the criterion) than sections with any other smooth variation of thickness. These particular sections are therefore optimum sections and, even if they may not be used in practice, provide a convenient yardstick for purposes of comparison. The buckling loads are considerably greater than those for the corresponding “constant thickness” sections.

End moments in open web steel joists

1980 ◽  
Vol 7 (1) ◽  
pp. 114-124
Author(s):  
S. C. Shrivastava ◽  
R. G. Redwood ◽  
P. J. Harris ◽  
A. A. Ettehadieh
Keyword(s):  
Significant Influence ◽  
The Other ◽  
Bending Moments ◽  
Axial Loads ◽  
Simply Supported ◽  
Gravity Load ◽  
Negative Bending

A study is made of the behaviour of open web steel joists having both top and bottom chords connected to a column when the end is subjected to negative bending moments. Six tests are described, three of which examine the behaviour with typical standard connections as detailed and supplied by manufacturers; the other three involve modifications to these connections in an attempt to minimize connection eccentricity. It is shown that the eccentricities inherent in the standard connections examined can have a significant influence on the behaviour and strength of a joist, whereas if the eccentricities are eliminated, reasonably predictable behaviour, based upon the member resistances under axial loads, can be achieved. These results are examined in relation to tie joists, which are designed to be simply supported under gravity load but have the bottom chord extended and attached to a column, and also in relation to joists designed as framing members.

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