Elastic Instability of Rectangular Sandwich Panel of Orthotropic Core With Different Face Thicknesses and Materials

1960 ◽  
Vol 27 (3) ◽  
pp. 474-480 ◽  
Author(s):  
C. C. Chang ◽  
I. K. Ebcioglu
Keyword(s):  
Sandwich Panel ◽  
Buckling Load ◽  
Shear Instability ◽  
Elastic Instability ◽  
Single Family ◽  
Buckling Behavior ◽  
Family Of Curves ◽  
Buckling Coefficient ◽  
Temperature Levels ◽  
Moduli Of Elasticity

This paper treats the instability of rectangular sandwich panels with nonisotropic cores and faces of different materials or thicknesses. The simply supported panel is loaded with a uniform edge compression. The solution is expressed in terms of a major buckling coefficient, given as the ratio of the critical lateral buckling load to the critical cylindrical buckling load, which is a function of several nondimensional parameters. A single family of curves shows the buckling behavior for all parameters. The effect of a moderate temperature differential between the two faces can be approximately considered by modifying their moduli of elasticity in accordance with their temperature levels. Besides the regular panel instability, a zone of core shear instability is determined and discussed in detail. Numerical examples are presented to illustrate the application of the analysis.

Deterministic and probabilistic buckling response of fiber–metal laminate panels under uniaxial compression

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Costas D. Kalfountzos ◽  
George S.E. Bikakis ◽  
Efstathios E. Theotokoglou
Keyword(s):  
Glass Fiber ◽  
Buckling Load ◽  
Sensitivity Analyses ◽  
Logarithmic Scale ◽  
Content Type ◽  
Buckling Behavior ◽  
Fiber Metal Laminate ◽  
Curvature Parameter ◽  
Buckling Coefficient ◽  
Fiber Metal

Purpose The purpose of this paper is to study the deterministic elastic buckling behavior of cylindrical fiber–metal laminate panels subjected to uniaxial compressive loading and the investigation of GLAss fiber-REinforced aluminum laminate (GLARE) panels using probabilistic finite element method (FEM) analysis. Design/methodology/approach The FEM in combination with the eigenvalue buckling analysis is used for the construction of buckling coefficient–curvature parameter diagrams of seven fiber–metal laminate grades, three glass-fiber composites and monolithic 2024-T3 aluminum. The influences of uncertainties concerning material properties and laminate dimensions on the buckling load are studied with sensitivity analyses. Findings It is found that aluminum has a stronger impact on the buckling behavior of the fiber–metal laminate panels than their constituent uni-directional or woven composites. For the classical simply supported boundary conditions, it is found that there is an approximately linear relation between the buckling coefficient and the curvature parameter when the diagrams are plotted in double logarithmic scale. The probabilistic calculations demonstrate that there is a considerable probability to overestimate the buckling load of GLARE panels with deterministic calculations. Originality/value In this study, the deterministic and probabilistic buckling response of fiber metal laminate panels is investigated. It is shown that realistic structural uncertainties could substantially affect the buckling strength of aerospace components.

scholarly journals Buckling Behavior of Sandwich Panel with Isotropic Core and Orthotropic Faces

2020 ◽  
Vol 9 (3) ◽  
pp. 294-297
Keyword(s):  
Sandwich Panel ◽  
Middle Layer ◽  
Buckling Load ◽  
Thin Layers ◽  
Fe Model ◽  
Buckling Behavior ◽  
End Conditions ◽  
Lightweight Structure ◽  
Support Conditions ◽  
Different Thickness

A sandwich panel is a lightweight structure, economical and having low thermal conductivity. It is made up of three layers in which the middle layer is called core which is bounded with thin layers at top and bottom called faces. Generally, the core has relatively low-density which makes it lightweight. The buckling load analysis of sandwich panel having isotropic core and orthotropic faces is studied for different support conditions using the FE based software ABAQUS. The FE model is validated with suitable published results. Then it is used to find critical buckling load of sandwich panel with isotropic core and orthotropic faces. Many new results have been presented for different thickness, end conditions, aspect ratio, etc.

Buckling and Post Buckling Behavior of a Transversely Stiffened Ship Hull Model

1964 ◽  
Vol 8 (04) ◽  
pp. 7-21
Author(s):  
H.G. Schultz
Keyword(s):  
Reasonable Agreement ◽  
Ship Hull ◽  
Buckling Load ◽  
Experimental Results ◽  
Postbuckling Behavior ◽  
Pure Bending ◽  
Box Girder ◽  
Buckling Behavior ◽  
Theoretical Investigations ◽  
Post Buckling

In the paper presented the behavior of a transversely formed box-girder model subjected to pure bending is discussed, where the deck plating of the model is loaded above the buckling load. The experimental results obtained are in reasonable agreement with theoretical investigations and show the influence of fabrication initiated plate deflections on the buckling and postbuckling behavior of the deck plating clearly. A method is suggested for determining the buckling load of plates having large initial deformations.

scholarly journals Influence of the patch loading length on the buckling coefficient of longitudinally stiffened plate girders

2019 ◽  
Author(s):  
Nelson Loaiza ◽  
Carlos Graciano ◽  
Rolando Chacón
Keyword(s):  
Elastic Buckling ◽  
Stiffened Plate ◽  
Element Analysis ◽  
Geometrical Properties ◽  
Plate Girders ◽  
Linear Finite Element ◽  
Aspect Ratios ◽  
Buckling Behavior ◽  
Buckling Coefficient ◽  
Patch Loading

This paper aims at investigating the effect of the bearing length on the elastic buckling behavior of longitudinally stiffened girder webs subjected to patch loading. Buckling coefficients are calculated by means of linear finite element analysis. Furthermore, a parametric analysis is performed to study the influence of other geometric parameters such as the panel aspect ratio and the geometrical properties of the longitudinal ones. Buckling coefficients of longitudinally stiffened girder webs are computed numerically. The results show that the buckling coefficient for longitudinally stiffener girder webs increases with the loading length. However, this conclusion is considerably affected by other factors such as the position of the stiffener, and panel aspect ratios.

scholarly journals Study on Buckling Behavior of Tapered Friction Piles in Soft Soils with Linear Shaft Friction

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junxiu Liu ◽  
Xianfeng Shao ◽  
Baoquan Cheng ◽  
Guangyong Cao ◽  
Kai Li
Keyword(s):  
Boundary Conditions ◽  
Soft Soil ◽  
Buckling Load ◽  
Lateral Stiffness ◽  
Equilibrium Equations ◽  
Tree Roots ◽  
Soft Soils ◽  
Buckling Behavior ◽  
Friction Pile ◽  
Shaft Friction

The buckling instability of long slender piles in soft soils is a key consideration in geoengineering design. By considering both the linear shaft friction and linear lateral stiffness of the soft soil, the buckling behaviors of a tapered friction pile embedded in heterogeneous soil are extensively studied. This study establishes and validates an analytical model to formulate the equilibrium equations and boundary conditions and then numerically solves the boundary value problem to obtain the critical buckling load and buckling shape by using software Matlab. The effects of boundary conditions, tapered ratio, stiffness ratio, friction ratio, lateral stiffness, and shaft friction on the buckling behavior of the friction pile are extensively explored. This study demonstrates that the buckling load decreases with the increase of friction ratio of the linear shaft friction. There exists an optimal tapered ratio corresponding to the maximum dimensionless buckling load in the tapered friction pile with linear shaft friction. The result means that the linear shaft friction should be considered in designing the tapered friction piles in heterogeneous soils. The results also have potential applications in the fields of growing of tree roots in soils, moving of slender rods in viscous fluids, penetrating of fine rods in soft elastomers, etc.

Buckling Analysis of Wind Power Tower Considering the Effect of Nonlinearity

2012 ◽  
Vol 256-259 ◽  
pp. 792-795
Author(s):  
Bo Song ◽  
Shuai Huang ◽  
Wen Shan He ◽  
Wei Wei
Keyword(s):  
Wind Power ◽  
Geometric Nonlinearity ◽  
Local Buckling ◽  
Element Model ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Nonlinear Buckling ◽  
Buckling Behavior ◽  
Geometry Nonlinearity ◽  
Material And Geometric Nonlinearity

Based on the 3D finite element model of the wind power tower, buckling behavior of the wind power tower in different wind directions is analyzed, and the effect considering geometry nonlinearity and considering the material and geometry nonlinearity to the buckling analysis is studied. The results show when the ratio of the radius of the tower drum and the length of the element is 18.75, the calculated precision can reach 95%. Local buckling of the wind power tower first appears, and buckling load and displacement considering the material and geometric nonlinearity reduce 52% and 58% compared with that only considering geometry nonlinearity. The linear and nonlinear buckling load of the wind power tower which is 90° sidewind are 1.8 and 1.2 times than those facing the wind direction.

Buckling Analysis of Symmetric Cross-Ply Laminated Annular Plates with Carbon Nanotubes

2014 ◽  
Vol 592-594 ◽  
pp. 901-905
Author(s):  
Pankaj Kumar ◽  
Pandey Ramesh
Keyword(s):  
Carbon Nanotubes ◽  
Boundary Condition ◽  
Carbon Nanotube ◽  
Aspect Ratio ◽  
Energy Method ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Buckling Loads ◽  
Annular Plates ◽  
Buckling Behavior

The Paper presents the buckling response of composite annular plates with under uniform internal and external radial edge loads using energy method. For the equation of stability Trefftez rule is used. The paper consists of buckling behavior of laminate (90/0) s, influence of some parameters such as thickness, boundary condition, aspect ratio on buckling loads and modes are investigated. Present results are compared with other papers. In this paper the effect of % weight of carbon nanotube (MWCNT) on the buckling load is also investigated.

The effects of cutouts on buckling behavior of composite plates

2012 ◽  
Vol 19 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Ahmet Erkliğ ◽  
Eyüp Yeter
Keyword(s):  
Fiber Orientation ◽  
Polymer Matrix Composites ◽  
Orientation Angle ◽  
Composite Plates ◽  
Buckling Load ◽  
Matrix Composites ◽  
Element Analysis ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Fiber Orientation Angle

AbstractCutouts such as circular, rectangular, square, elliptical, and triangular shapes are generally used in composite plates as access ports for mechanical and electrical systems, for damage inspection, to serve as doors and windows, and sometimes to reduce the overall weight of the structure. This paper addresses the effects of different cutouts on the buckling behavior of plates made of polymer matrix composites. To study the effects of cutouts on buckling, loaded edges are taken as fixed and unloaded edges are taken as free. Finite element analysis is also performed to predict the effects of different geometrical cutouts, orientations, and position of cutouts on the buckling behavior. The results show that fiber orientation angle and cutout sizes are the most important parameters on the buckling loads. For all types of cutouts the buckling loads decrease dramatically by increasing the fiber orientation angle. It is observed that minimum buckling load is reached when 45° fiber angle is used, and after this angle critical buckling load begins to increase. Also, it is concluded that while fiber orientation angle is 0°, elliptical cutout has the highest buckling load and while fiber orientation angle is 45°, circular cutout has the highest buckling load.

Buckling Analysis of Drill Strings in Inclined Wellbores Using the Explicit Finite Element Method

2012 ◽  
Author(s):  
Mehdi Hajianmaleki ◽  
Jeremy S. Daily ◽  
Lev Ring ◽  
Raju Gandikota
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Drill Pipe ◽  
Drill String ◽  
Buckling Load ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Buckling Behavior ◽  
Inclination Angles ◽  
Element Method

Understanding drill string buckling behavior is a significant challenge to the petroleum industry. In this paper, the explicit finite element method implemented in Abaqus software is employed to study the buckling of drill strings for inclined straight wellbores. Classic solutions for the critical buckling length of self-weighted columns as well as critical buckling load for drill pipe inside inclined wellbores are compared to explicit FEA and accurate results are provided by the finite element based predictions. The effect of different inclination angles and string effective weight due to the buoyancy effect has been studied and the results for sinusoidal and helical buckling are compared to analytical results and experimental data in the literature. The theoretical predictions for different inclination angles agree with the simulations. Theoretical buckling load of inclined drill strings approaches zero by decreasing the effective weight of a floating drill string. However, the results of finite element simulations show that significant buckling load would still exist for very low drill string effective weight. These results are confirmed by experimental results provided by other researchers. Overall, the efficacy of using explicit finite element methods to model drill string buckling behavior is demonstrated.

Nonlinear Equilibrium and Buckling of Fixed Shallow Arches Subjected to an Arbitrary Radial Concentrated Load

2017 ◽  
Vol 17 (08) ◽  
pp. 1750082 ◽  
Author(s):  
Yong-Lin Pi ◽  
Mark Andrew Bradford ◽  
Airong Liu
Keyword(s):  
Analytical Solutions ◽  
Limit Point ◽  
Buckling Load ◽  
Equilibrium Path ◽  
Instability Mode ◽  
Concentrated Load ◽  
Shallow Arches ◽  
Buckling Behavior ◽  
Nonlinear Equilibrium ◽  
Relationship Of

This paper is concerned with an analytical study of the nonlinear in-plane equilibrium and buckling of fixed shallow circular arches that are subjected to an arbitrary radial concentrated load. The structural behavior of an arch under an arbitrary radial concentrated load is quite different from that of an arch under a central concentrated load. It is shown that a fixed arch under an arbitrary radial concentrated load can buckle in a limit point instability mode, but cannot buckle in a bifurcation mode, which is different from that of a fixed arch under a central concentrated load that can buckle in a bifurcation mode or in a limit point instability mode. Analytical solutions for the nonlinear equilibrium path and limit point buckling load of shallow circular arches under an arbitrary radial concentrated load are derived. It is found that the load position influences the buckling load significantly and the influence is much related to the modified slenderness of the arch defined in the paper. It is also found that when the modified slenderness of an arch is smaller than a specific value, the arch has no typical buckling behavior. The analytical solution for the relationship of the specific modified slenderness with the load position is also derived. Comparisons with finite element (FE) results show that the analytical solutions can accurately predict the nonlinear equilibrium and buckling load of shallow fixed arches under an arbitrary radial concentrated load.

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