• Steel and Composite Structures
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• v.43 no.6
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• pp.725-734
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• 2022

In this paper, buckling analyses of nanocomposite plate reinforced by Graphen platelet (GPL) is studied. The Halphin-Tsai model is used for obtaining the effective material properties of nanocomposite plate. The nanocomposite plate is modeled by Third order shear deformation theory (TSDT). The elastic medium is simulated by Winkler model. Employing relations of strains-displacements and stress-strain, the energy equations of the plate are obtained and using Hamilton's principle, the governing equations are derived. The governing equations are solved based on analytical solution. The effect of GPL volume percent, geometrical parameters of plate and elastic foundation on the buckling load are investigated. Results show that with increasing GPLs volume percent, the buckling load increases. In addition, elastic medium can enhance the values of buckling load significantly.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.449-458
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• 2012

Finite element buckling analysis of insulated transition flue ducts is carried out to determine the critical buckling load multipliers when subjected to axial compression for design process. Through this investigation, the results of numerical computations to examine the buckling strength for different possible duct shapes (cylinder, and circular-to-square) are presented. The load multipliers are determined through detailed buckling analysis taking into account the effects of geometrical construction and duct plate thickness which have great influence on the buckling load. Enhancement in the buckling capacity of such ducts by the addition of horizontal and vertical stiffeners is also investigated. Several models with varying dimensions and plate thicknesses are examined to obtain the linear buckling capacities against duct dimensions. The percentage improvement in the buckling capacity due to the addition of vertical stiffeners and horizontal Stiffeners is shown to be as high as three times for some cases. The study suggests that the best location of the horizontal stiffener is at 0.25 of duct depth from the bottom to achieve the maximum buckling capacity. A design equation estimating the buckling strength of geometrically perfect cylindrical-to-square shell is developed by using regression analysis accurately with approximately 4% errors.

• Steel and Composite Structures
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• v.13 no.4
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• pp.367-382
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• 2012

This paper is dedicated to the buckling behaviors of strengthened perforated plates under edge shear loading, which is a typical load pattern of steel plates in civil engineering, especially in plate and box girders. The square plates considered each has a centric circular hole and is simply supported on four edges in the out-of-plane direction. Three types of strengthening stiffeners named ringed stiffener (RS), flat stiffener (FSA and FSB) and strip stiffener (SSA, SSB and SSC) are mainly discussed. The finite element method (FEM) has been employed to analyse the elastic and elasto-plastic buckling behavior of unstrengthened and strengthened perforated plates. Results show that most of the strengthened perforated plates behave higher buckling strengths than the unstrengthened ones, while the enhancements in elastic buckling stress and elasto-plastic ultimate strength are closely related to stiffener types as well as plate geometric parameters including plate slenderness ratio and hole diameter to plate width ratio. The critical slenderness ratios of shear loaded strengthened perforated plates, which determine the practical buckling pattern (i.e., elastic or elasto-plastic buckling) of the plates, are also studied. Based on the contrastive analyses of strengthening efficiency considering the influence of stiffener consumption, the most efficient cutout-strengthening methods for shear loaded perforated square plates with different slenderness ratios and circular hole diameter to plate width ratios are preliminarily identified.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.173-181
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• 2000

The stability of a structural plate is a crucial problem which causes wrinkling and buckling. In this paper, the effect of the pattern of spot-welding points in the two rectangular plate on the shear buckling load is studied with respect to the thickness, the aspect ratio of plates, the number of welding spots. Buckling coefficient of the simple plate was compared with that of two plates with various conditions to extract the effect of buckling strength. The effect of the number of welding spots are studied in two directions, longitudinal and transverse directions. The concluded that the reinforcement effect was maximized when the aspect ratio was close to 1.5 and that the effect of number of welding spots in longitudinal direction was larger than that in transverse direction.

• Computers and Concrete
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• v.23 no.4
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• pp.295-301
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• 2019

In this paper, buckling analyses of composite concrete plate reinforced by piezoelectric nanoparticles is studied. The Halphin-Tsai model is used for obtaining the effective material properties of nano composite concrete plate. The nano composite concrete plate is modeled by Third order shear deformation theory (TSDT). The elastic medium is simulated by Winkler model. Employing nonlinear strains-displacements, stress-strain, the energy equations of concrete plate are obtained and using Hamilton's principal, the governing equations are derived. The governing equations are solved based on Navier method. The effect of piezoelectric nanoparticles volume percent, geometrical parameters of concrete plate and elastic foundation on the buckling load are investigated. Results showed that with increasing Piezoelectric nanoparticles volume percent, the buckling load increases.

• Journal of Korean Association for Spatial Structures
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• v.21 no.4
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• pp.57-64
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• 2021

This paper conducted a comparative analysis of the shear buckling characteristics of trapezoidal and sinusoidal corrugated steel plates considering of their initial imperfection. Initial imperfection refers to the state where the shape of the corrugated plate is initially not perfect. As such, an initially imperfect shape was assumed using the eigen buckling mode. To calculate the buckling stress of corrugated steel plates, the linear buckling analysis used a boundary condition which was applied to the plate buckling analysis. For the comparison of trapezoidal and sinusoidal corrugation, the shape parameters were assumed using the case where the length and slope of each corrugation were the same, and the initial imperfection was considered to be from 0.1% to 5% based on the length of the steel plate. Here, for the buckling analysis, ANSYS, a commercial FEA program, was used. From the results of buckling analysis, the effect of overall initial imperfection showed that the larger the initial imperfection, the lower the buckling stress. However, in the very thin model, interaction or local buckling was dominant in the perfect shape, and in this case, the buckling stress did not decrease. Besides, the sinusoidal model showed higher buckling stress than the trapezoidal one, and the two corrugation shapes decreased in a similar way.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.5-8
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• 2000

This paper presents the results of an elastic buckling analysis of orthotropic plate under in-plane linearly distributed forces. The analytical solution for the orthotropic plate whose boundaries were assumed to be simply supported was derived in the previous work. In this study the loaded edges of plate are assumed to be simply supported and other two edges are assumed to be fixed. For the buckling analysis Rayleigh-Ritz method is employed. Graphical form of results for finding the elastic buckling strength of orthotropic plate under in-plane linearly distributed forces is presented.

• Structural Engineering and Mechanics
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• v.64 no.6
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• pp.751-763
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• 2017

This article deals with the buckling behaviour of multilayered magneto-electro-elastic (MEE) plate subjected to uniaxial and biaxial compressive (in-plane) loads. The constitutive equations of MEE material are used to derive a finite element (FE) formulation involving the coupling between electric, magnetic and elastic fields. The displacement field corresponding to first order shear deformation theory (FSDT) has been employed. The in-plane stress distribution within the MEE plate existing due to the enacted force is considered to be equivalent to the applied in-plane compressive load in the pre-buckling range. The same stress distribution is used to derive the potential energy functional. The non-dimensional critical buckling load is accomplished from the solution of allied linear eigenvalue problem. Influence of stacking sequence, span to thickness ratio, aspect ratio, load factor and boundary condition on critical buckling load and their corresponding mode shape is investigated. In addition, static deflection of MEE plate under the sinusoidal and the uniformly distributed load has been studied for different stacking sequences and boundary conditions.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.13-16
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• 2001

This paper presents the results of an elastic buckling analysis of isosceles trapezoidal orthotropic plate. In this study, all edges of plate are assumed to be simply supported and the difference of the applied loads are assumed to be taken out by shear of constant intensity along the sloping sides. For the buckling analysis, collocation method is employed. Finite element analysis is also conducted and the results are compared with theoretical ones.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.25-28
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• 2001

The problem considered is the buckling of a rectangular orthotropic plate, tapered in thickness in a direction parallel to two sides and compressed in that direction. Curves are presented showing the variation of buckling stress coefficient with the special loads. The type of thickness variation is exponential. While this paper is presented how to design for an efficient orthotropic plate taper from physical consideration.