BUCKLING OF COMPOSITE PLATES WITH ARBITRARY BOUNDARY CONDITIONS BY A SEMI-ANALYTICAL APPROACH

2012 ◽  
Vol 12 (05) ◽  
pp. 1250033 ◽  
Author(s):  
EUGENIO RUOCCO ◽  
VINCENZO MINUTOLO
Keyword(s):  
Analytical Approach ◽  
Composite Plates ◽  
Analytical Form ◽  
Biaxial Compression ◽  
Rectangular Plates ◽  
Arbitrary Boundary ◽  
Buckling Loads ◽  
Plate Buckling ◽  
Out Of Plane ◽  
Plane Displacement

A semi-analytical approach for the buckling analysis of symmetrically laminated rectangular plates under arbitrary constrains is presented. In the proposed method, the out-of-plane displacement field is assumed to be of a multiplicative form containing two vectors of functions, one being prescribed and the other to be determined, depend on separate variables. As a consequence, one may solve the equilibrium equation analytically, and obtain exact buckling loads for the biaxial compression and different boundary constrains. Several cases of plate buckling under different load combinations are studied, in order to demonstrate the applicability of the proposed approach. The results obtained are compared with the existing ones, where available in analytical form, and approximate results obtained by other numerical methods.

A GENERALIZED ANALYTICAL APPROACH FOR THE BUCKLING ANALYSIS OF THIN RECTANGULAR PLATES WITH ARBITRARY BOUNDARY CONDITIONS

2011 ◽  
Vol 11 (01) ◽  
pp. 1-21 ◽  
Author(s):  
EUGENIO RUOCCO ◽  
VINCENZO MINUTOLO ◽  
STEFANO CIARAMELLA
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Analytical Approach ◽  
Elastic Stability ◽  
Rectangular Plates ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Arbitrary Boundary ◽  
Arbitrary Boundary Conditions ◽  
Numerical Discretization

An analytical approach for studying the elastic stability of thin rectangular plates under arbitrary boundary conditions is presented. Because the solution is given in closed-form, the approach can be regarded as "exact" under the Kirchhoff–Love assumption. The proposed procedure allows us to obtain the buckling load and modal displacements that do not depend on the number of elements adopted in the numerical discretization using, say, the finite element method. Due to the fact that the longitudinal variation of the displacements is taken into account, the two-dimensional model established for the plate is considered "complete." Such an approach overcomes the shortcomings of conventional modeling presented in the literature. In order to demonstrate the generality of the proposed approach, several examples are prepared and the results obtained are compared with finite element and analytical solutions existing elsewhere.

scholarly journals Exact strip postbuckling analysis of composite plates under compression and shear

2019 ◽  
Vol 123 (1263) ◽  
pp. 658-677
Author(s):  
K. Zhao ◽  
D. Kennedy ◽  
C.A. Featherston
Keyword(s):  
Finite Element ◽  
Composite Plates ◽  
Mode Shapes ◽  
Computational Time ◽  
Shear Load ◽  
Element Analysis ◽  
Lagrangian Multipliers ◽  
Buckling Loads ◽  
Finite Strip ◽  
Out Of Plane

ABSTRACTStiffened wing and fuselage panels often have a postbuckling reserve of strength, enabling them to carry loads far in excess of their critical buckling loads. Therefore allowing for postbuckling in design can reduce their weight, hence reducing fuel consumption and environmental impact. The present paper extends the postbuckling analysis in the exact strip software VICONOPT to more accurately reflect the skewed mode shapes arising from shear load and anisotropy. Such mode shapes are represented by a series of sinusoidal responses with different half-wavelengths which are coupled together using Lagrangian multipliers to enforce the boundary conditions. In postbuckling analysis the in-plane deflections involve responses with additional half-wavelengths which are absent from the out-of-plane deflection series. Numerical results are presented and compared with finite element analysis for validation. The present analysis gives close results compared to the finite element and finite strip methods and saves computational time significantly.

A new design approach for the determination of the buckling load of rectangular plates

2012 ◽  
Vol 227 (7) ◽  
pp. 1417-1428
Author(s):  
H Ahmed ◽  
JF Durodola ◽  
RG Beale
Keyword(s):  
Analysis Procedure ◽  
Preliminary Design ◽  
Rectangular Plates ◽  
Finite Element Analyses ◽  
Support Condition ◽  
Plate Edge ◽  
Buckling Loads ◽  
Plate Buckling ◽  
Good Agreement

The objective of this article is to introduce and assess a new plate buckling analysis procedure which can be used for quick, approximate analysis of buckling loads in preliminary design. The method is applied to a range of plate edge support condition combinations including many where results are not readily available. The results obtained using the new procedure were compared against theoretical formulae available in the literature and by finite element analyses with good agreement.

Analytical Buckling Loads of Composite Rectangular Plates with Vertical and Rotational Springs Along the Edges

2020 ◽  
pp. 2043002
Author(s):  
Joseph Tenenbaum ◽  
Moshe Eisenberger
Keyword(s):  
Boundary Conditions ◽  
Bending Moment ◽  
Composite Plates ◽  
Static Solution ◽  
Published Data ◽  
Rectangular Plates ◽  
Buckling Loads ◽  
Edge Conditions ◽  
In Series ◽  
Edge Force

In this research, a new analytical solution is used for finding the buckling loads of rectangular plates with vertically and rotationally restrained edges. The solution method in this study is based on the development of a static solution for a plate. The solution is obtained in series form, and the coefficients are solved to match the edge conditions. The solution fits all the combinations of possible boundary conditions, of the deflection, slope, shear force and bending moment along the edges of the plate. In the case of springs, the edge force and moment boundary conditions are modified to include these effects. Any number of edges, from one to four, with both types of stiffening springs can be solved. Using this new method, the exact buckling loads and modes are found. The results are verified with published data, and many new cases are presented for uni-axially and bi-axially loaded isotropic, orthotropic, and composite plates.

Characterization and optimization of hybrid carbon–glass epoxy composites under combined loading

2019 ◽  
Vol 53 (18) ◽  
pp. 2593-2605 ◽  
Author(s):  
V Infante ◽  
JFA Madeira ◽  
Rui B Ruben ◽  
F Moleiro ◽  
Sofia Teixeira de Freitas
Keyword(s):  
Hybrid Composite ◽  
Composite Plates ◽  
Experimental Tests ◽  
Combined Loading ◽  
Design Variables ◽  
Out Of Plane ◽  
Global And Local Optimization ◽  
Plane Displacement ◽  
Global And Local ◽  
Hybrid Carbon

This work is intended to characterize the mechanical behavior of hybrid carbon–glass composite plates under combined loading of bending and torsion, and to determine the optimal ply fiber orientations to minimize the maximum out-of-plane displacement under such loading conditions. Hybrid composite plates were manufactured with 10 plies each and different stacking sequences using hand lay-up, with carbon fiber and glass fiber reinforcements in an epoxy matrix. Two experimental setups (involving two distinct boundary conditions) are here considered to test the composite plates, both simulating combined loading of bending and torsion. Numerical simulations of the experimental tests were performed in ABAQUS® and validated with the experimental data. Using the ply fiber orientations as design variables, the hybrid composite plates were then optimized using global and local optimization using direct search (GLODS). The objective function of minimization of the maximum out-of-plane displacement is carried out through an interactive cycle between GLODS and ABAQUS®. Specimens of three optimized laminates were also manufactured for experimental validation. The optimization process contributed to improve the performance of the hybrid composite plates in more than 30% when compared to some non-optimized plates.

Deformation in Impacted Stitched Composite Plates Subjected to Compressive Load

2011 ◽  
Vol 393-395 ◽  
pp. 36-39
Author(s):  
Jiang Tao Ruan ◽  
Shi Bin Wang ◽  
Jing Wei Tong ◽  
Min Shen ◽  
Francesco Aymerich ◽  
...  
Keyword(s):  
Speckle Pattern ◽  
Compressive Load ◽  
Composite Plates ◽  
Low Velocity Impact ◽  
Electronic Speckle Pattern Interferometry ◽  
Low Velocity ◽  
Out Of Plane ◽  
Compressive Loads ◽  
Graphite Fibre ◽  
Plane Displacement

The study on deformation in impact-damaged graphite-fibre/epoxy stitched composite plates subjected to compressive load is presented. A delaminated cross-ply laminate [03/903]S obtained in low-velocity impact test has been examined using a self-designed anti-buckling device in compressive experiment. The out-of-plane displacement field of the specimen has been measured with an optical whole-filed measurement technique, which is carrier electronic speckle pattern interferometry (carrier-ESPI). Finite element (FE) simulation is also carried out to predict the deformation. The effect of the stitching line on compressive deformation is discussed for various stitched laminates. Finally, the numerical results are compared with experimental measurement deformations under different compressive loads.

Maximizing the buckling loads of symmetrically laminated composite rectangular plates using a layerwise optimization approach

2004 ◽  
Vol 218 (7) ◽  
pp. 681-691 ◽  
Author(s):  
Y Narita ◽  
G J Turvey
Keyword(s):  
Laminated Composite ◽  
Computational Effort ◽  
Laminated Plates ◽  
Simultaneous Optimization ◽  
Biaxial Compression ◽  
Optimization Approach ◽  
Rectangular Plates ◽  
Buckling Loads ◽  
Edge Conditions ◽  
Optimum Solution

Research on optimum lay-ups and buckling loads of laminated plates is briefly reviewed. A new sequential, iterative procedure, known as layerwise optimization (LO), for determining the optimum lay-ups and maximum buckling loads of symmetrically laminated rectangular plates is described. The physical basis of the procedure is explained. LO is shown to be highly efficient, with reductions in computational effort of more than 99 per cent being possible in comparison to some simultaneous optimization procedures. Three examples are presented of the use of the LO procedure to determine the optimum lay-ups and associated maximum buckling loads of 8- and 24-layer symmetrically laminated rectangular plates subjected to uniform, uniaxial and biaxial compression. For 18 combinations of free, simply supported and clamped edge conditions, it is shown that the LO procedure generally leads to the optimum solution. In the very few instances where a local rather than a global solution was obtained, the maximum buckling load was only 4–6.5 per cent lower than the optimum value.

Dynamic Buckling Response of Long Plates for the Prediction of Local Plate Buckling of Corrugated Core Sandwich Columns

2015 ◽  
Vol 82 (11) ◽  
Author(s):  
Jae-Yong Lim ◽  
Hilary Bart-Smith
Keyword(s):  
Model Development ◽  
Local Buckling ◽  
Longitudinal Direction ◽  
Plate Buckling ◽  
Proposed Model ◽  
Constant Rate ◽  
Out Of Plane ◽  
Alternative Methodology ◽  
Buckling Failure ◽  
Plane Displacement

An analytical model predicting the dynamic local buckling failure of plates with a large dimension in the longitudinal direction compressed at a constant rate was proposed. The model began with the hypothesis that the proposed analytical approach could be an alternative methodology to approximate the dynamic local plate buckling response of constituent plates of corrugated core sandwich columns. Prior to the model development, four preliminary finite-element (FE) simulations were conducted to observe the typical dynamic response of the sandwich columns having thin core web plates or thin face sheets. From the simulations, several wrinkles with a regular pattern were generated, and then one of the wrinkles grew excessively to a failure. Accordingly, the proposed model considered an imaginary patch plate on a long plate simulating a face sheet or a core web plate. The size of the patch plate was predefined so as to encompass the major growing wrinkle, and the out-of-plane displacement was calculated till load drop. The verification of the proposed model was followed by comparison with the FE calculations. The model was satisfactory in predicting maximum forces and times-to-failure, but some discrepancies were found when postcritical behavior and plasticity were involved. The sources of the discrepancies were discussed.

Buckling Analysis of Delaminated and Stitched Composite Plate System Under Hygrothermal Pressure

2005 ◽  
Vol 128 (1) ◽  
pp. 117-122 ◽  
Author(s):  
S. Leigh Phoenix ◽  
A. Kadir Yavuz ◽  
Katerina D. Papoulia ◽  
C. Yuen Hui
Keyword(s):  
Composite Plate ◽  
Adhesive Layer ◽  
Mode Shapes ◽  
Rectangular Plates ◽  
Matrix Composites ◽  
Algebraic Equations ◽  
Buckling Loads ◽  
Out Of Plane ◽  
Compressive Loads ◽  
The Matrix

In this study, we develop a model for buckling of a partially delaminated composite plate with transverse stitching to resist out of plane deformations. The model applies to carbon fiber/polyimide matrix composites rapidly heated to around 370 °C, where it is known that steam-induced delamination (the popcorn effect) becomes an issue as the pressures generated approach the tensile strength of the matrix. Thus, a key element is the incorporation of this hygrothermal pressure within the formulation. This complex composite structure is modeled as two adhesively connected, specially orthotropic, rectangular plates, and the delaminations with internal vapor pressure are considered as holes in the adhesive layer. The intact regions of the adhesive layer and the stitches are modeled by continuous and discrete linear mechanical springs, respectively. The energy contributions of each component in the system are expressed in terms of out-of-plane displacements. The boundary conditions are that the system is simply supported along all edges so as to permit a Fourier sine series to approximate the transverse displacements. Application of the energy minimization approach gives a system of algebraic equations to determine the unknown weighting coefficients of the functions describing the transverse deflections of each plate layer. Deformed shapes of the system under axial compressive loads are obtained for different hygrothermally induced pressure conditions so as to show that the model works well. Parametric studies on critical buckling loads are performed for a few stitch and delamination configurations. It is found that stitching through delaminated areas can increase critical buckling loads and alter the sequence of corresponding mode shapes.

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