Buckling Behaviour of the Delaminated Sandwich Plates under Combined Loads

2014 ◽  
Vol 601 ◽  
pp. 88-91
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica
Keyword(s):  
Axial Compression ◽  
Composite Plates ◽  
Sandwich Composite ◽  
Sandwich Plates ◽  
Compression Loading ◽  
Numerical Tests ◽  
Boundary Shear ◽  
Combined Loads ◽  
Hull Structure ◽  
Loading Ratio

In the paper, a methodology to evaluate the influence of the central circular delamination on the buckling and postbuckling behaviour of the sandwich plates under shear and compression loading, used in ship hull structure, is presented. The parametric calculus was done for various values of loading ratios. The numerical tests on the delaminated plates are presented. Sandwich composite plates containing central delaminations are analyzed with respect to combined boundary shear and axial compression buckling. Finally, the graphical results for all values of loading ratio are presented.

scholarly journals Free vibration and dynamic response of sandwich composite plates with auxetic honeycomb core

2021 ◽  
Vol 15 (4) ◽  
pp. 1-14
Author(s):  
Tran Huu Quoc ◽  
Tran Minh Tu ◽  
Vu Van Tham
Keyword(s):  
Free Vibration ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Core Layer ◽  
Element Model ◽  
Dynamic Responses ◽  
Sandwich Composite ◽  
Geometrical Parameters ◽  
Sandwich Plates ◽  
Discrete Shear Gap

This paper deals with the free vibration and dynamic responses of composite sandwich plates. The sandwich plate has three layers in which two face sheets are made of isotropic material, and the core layer is made of auxetic honeycomb structures with a negative Poisson's ratio.  A smoothed finite element model based on the first-order shear deformation theory is established for the analysis purpose. In the model, only the linear approximation is necessary, and the discrete shear gap method for triangular plate elements is used to avoid the shear locking. The Newmark direct integration technique is used to capture the dynamic responses of the sandwich plates. The convergence study is made, and the accuracy of present results is validated by comparison with available data in the literature. The influence of geometrical parameters, material properties, and boundary conditions are explored and discussed. Numerical results show that auxetic materials have several different responses compared to conventional materials, and these behaviors are strongly influenced by the internal structure of the auxetic material.

scholarly journals STATIC BENDING STRENGTH OF SANDWICH COMPOSITE PLATES WITH TETRACHIRAL HONEYCOMBS

2021 ◽  
Vol 17 (3) ◽  
pp. 102-113
Author(s):  
Alexey Mazaev ◽  
Marina Shitikova
Keyword(s):  
Relative Density ◽  
Bending Strength ◽  
Composite Plates ◽  
Core Layer ◽  
Theory Of Elasticity ◽  
Sandwich Composite ◽  
Constant Thickness ◽  
Strength Analysis ◽  
Sandwich Plates ◽  
Honeycomb Core

The article presents a numerical strength analysis of sandwich plates with solid face layers and tetrachiral honeycomb core layer under static bending conditions. An aluminum alloy was chosen as the material of plates. For honeycomb core layers, the discretization (number of unit cells) and the relative density were varied with a constant thickness. Calculations were performed for the case of bending with rigidly clamped ends and three-point bending within the framework of the theory of elasticity by the finite element method. The strength analysis enables one to determine the load values, at which the maximal stresses according to the von Mises criterion were equal to the conventional yield stress of the material. The aim of this work is to study the effect of discretization and relative density of honeycomb core layers of tetrachiral type on the str ength of sandwich plates.

Static analysis of laminated and sandwich composite plates based on simple refined higher-order displacement theory

2010 ◽  
Vol 32 (2) ◽  
pp. 95-106
Author(s):  
Tran Minh Tu
Keyword(s):  
Finite Element ◽  
Static Analysis ◽  
Composite Plates ◽  
Higher Order ◽  
Sandwich Composite ◽  
Sandwich Plates ◽  
Present Formulation ◽  
Numerical Examples ◽  
Displacement Theory ◽  
Different Thickness

A simple refined higher-order displacement theory is used for the static analysis of laminated and sandwich plates. Both analytical and finite element solutions are developed. Numerical examples of laminated and sandwich plates are given for different thickness ratios, length-to-thickness ratios to illustrate the accuracy of the present formulation by comparing the present results with results already available in the literature.

A data mining approach to the diagnosis of failure modes for two serial fastened sandwich composite plates

2016 ◽  
Vol 51 (20) ◽  
pp. 2853-2862 ◽  
Author(s):  
Serkan Ballı
Keyword(s):  
Data Mining ◽  
Random Forest ◽  
Failure Modes ◽  
Composite Plates ◽  
Study Data ◽  
Sandwich Composite ◽  
Support Vector ◽  
Geometrical Parameters ◽  
Mining Methods

The aim of this study is to diagnose and classify the failure modes for two serial fastened sandwich composite plates using data mining techniques. The composite material used in the study was manufactured using glass fiber reinforced layer and aluminum sheets. Obtained results of previous experimental study for sandwich composite plates, which were mechanically fastened with two serial pins or bolts were used for classification of failure modes. Furthermore, experimental data from previous study consists of different geometrical parameters for various applied preload moments as 0 (pinned), 2, 3, 4, and 5 Nm (bolted). In this study, data mining methods were applied by using these geometrical parameters and pinned/bolted joint configurations. Therefore, three geometrical parameters and 100 test data were used for classification by utilizing support vector machine, Naive Bayes, K-Nearest Neighbors, Logistic Regression, and Random Forest methods. According to experiments, Random Forest method achieved better results than others and it was appropriate for diagnosing and classification of the failure modes. Performances of all data mining methods used were discussed in terms of accuracy and error ratios.

Collapse of Tubes Under Combined Bending and Axial Compression Loads

2018 ◽  
Author(s):  
Shan Jin ◽  
Shuai Yuan ◽  
Yong Bai
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Axial Compression ◽  
Local Buckling ◽  
Practical Application ◽  
Buckling Modes ◽  
Combined Loads ◽  
Bending Loads ◽  
Good Agreement

In practical application, pipelines will inevitably experience bending and compression during manufacture, transportation and offshore installation. The mechanical behavior of tubes under combined axial compression and bending loads is investigated using experiments and finite element method in this paper. Tubes with D/t ratios in the range of 40 and 97 are adopted in the experiments. Then, the ultimate loads and the local buckling modes of tubes are studied. The commercial software ABAQUS is used to build FE models to simulate the load-shortening responses of tubes under combined loads. The results acquired from the ABAQUS simulation are compared with the ones from verification bending experiment, which are in good agreement with each other. The models in this paper are feasible to analyze the mechanical properties of tubes under combined axial compression and bending loads. The related results may be of interest to the manufacture engineers.

scholarly journals Vibration of Skew Sandwich Plates With Laminated Facings

1997 ◽  
Author(s):  
C. M. Wang ◽  
K. K. Ang ◽  
C. Wang
Keyword(s):  
Ritz Method ◽  
Composite Plates ◽  
Sandwich Plates ◽  
Rectangular Plates ◽  
Vibration Frequencies ◽  
Edge Conditions ◽  
System Vibration ◽  
Special Case ◽  
Length Limitation ◽  
Good Agreement

A Rayleigh-Ritz analysis is presented for the free vibration of skew sandwich plates composed of an orthotropic core and laminated facings. By proposing a set of Ritz functions consisting of the product of mathematically complete polynomial functions and the the boundary equations raised to appropriate powers, the Rayleigh-Ritz method can be automated to handle such composite plates with any combination of edge conditions. For convenience and better accurarcy, the Ritz formulation was derived in the skew coordinate system. Vibration frequencies of rectangular plates (a special case of skew plates) obtained via this method have been found to be in good agreement with previous researchers results. Owing to length limitation, only sample vibration frequencies for skew sandwich plates are presented.

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