Delamination in laminated plates using the 4-noded quadrilateral QLRZ plate element based on the refined zigzag theory

2014 ◽  
Vol 108 ◽  
pp. 456-471 ◽  
Author(s):  
A. Eijo ◽  
E. Oñate ◽  
S. Oller
Keyword(s):  
Laminated Plates ◽  
Plate Element ◽  
Zigzag Theory

scholarly journals A new finite element for free vibration analysis of stiffened composite plates

2007 ◽  
Vol 29 (4) ◽  
pp. 529-538 ◽  
Author(s):  
Tran Ich Thinh ◽  
Ngo Nhu Khoa
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Plate Theory ◽  
Free Vibration Analysis ◽  
Composite Plates ◽  
Laminated Plates ◽  
Triangular Element ◽  
Plate Element ◽  
Stiffened Plate

A new 6-noded stiffened triangular plate element for the analysis of stiffened composite plates based on Mindlins deformation plate theory has been developed. The stiffened plate element is a combination of basic triangular element and bar component. The element can accommodate any number of arbitrarily oriented stiffeners and obviates the use of mesh lines along the stiffeners. Free vibration analyses of stiffened laminated plates have been carried out with this element and the results are compared with those published. The finite element results show very good matching with the experimental ones.

An accurate zigzag theory for bending and buckling analysis of thick laminated sandwich plates with soft core

2020 ◽  
Vol 54 (18) ◽  
pp. 2473-2488
Author(s):  
Qilin Jin ◽  
Weian Yao
Keyword(s):  
Transverse Shear ◽  
Buckling Analysis ◽  
Soft Core ◽  
Shear Stresses ◽  
Sandwich Plates ◽  
Plate Element ◽  
Proposed Model ◽  
Transverse Shear Stresses ◽  
Zigzag Theory ◽  
Benchmark Solutions

An accurate and computationally attractive zigzag theory is developed for bending and buckling analysis of thick laminated soft core sandwich plates. The kinematic assumptions of the proposed zigzag theory are obtained by superimposing a nonlinear zigzag function on the first-order shear deformation theory. In order to obtain the accurate transverse shear stresses, a preprocessing approach based on the three-dimensional equilibrium equations and the Reissner mixed variational theorem is used. It is significant that the second-order derivatives of in-plane displacement variables have been removed from the transverse shear stresses, such that the finite element implementation is greatly simplified. Thus, based on the proposed zigzag model, a computationally efficient four-node C0 quadrilateral plate element with linear interpolation function is proposed for bending and buckling analysis of soft core sandwich plates. The advantage of the present formulation is that no post-processing approach is needed to calculate the transverse shear stresses while maintaining the computational accuracy of a linear plate element. Moreover, the accurate transverse shear stresses can be involved in the strain energy which can actively improve the accuracy of critical loads. Performance of the proposed model is assessed by comparing with several benchmark solutions. Agreement between the present results and the reference solutions is very good, and the proposed model only includes the seven displacement variables which can demonstrate the accuracy and effectiveness of the proposed model.

Efficient Global Zigzag Theory for Elastic Laminated Plates

2008 ◽  
Vol 28 (9) ◽  
pp. 1025-1047 ◽  
Author(s):  
P. Kumari ◽  
J.K. Nath ◽  
S. Kapuria ◽  
P.C. Dumir
Keyword(s):  
Laminated Plates ◽  
Zigzag Theory

Non-polynomial zigzag theories with C° finite element formulation for buckling analysis of laminated composite and sandwich plates

2021 ◽  
pp. 095440622110200
Author(s):  
Suganyadevi Sarangan ◽  
BN Singh
Keyword(s):  
Transverse Shear ◽  
Laminated Composite ◽  
Buckling Analysis ◽  
Laminated Plates ◽  
Load Parameter ◽  
Shear Stresses ◽  
Element Formulation ◽  
Sandwich Plates ◽  
Plane Displacement ◽  
Zigzag Theory

In this present work, non-polynomial zigzag theories (algebraic zigzag theory (AZT), exponential zigzag theory (EZT), hyperbolic zigzag theory (HZT), inverse hyperbolic zigzag theory (IZT), logarithmic zigzag theory (LZT) and trigonometric zigzag theory (TZT)) are performed for buckling response of laminated composite and sandwich plates. The present models assume parabolic variation of out – plane stresses through the depth of the plate and also accomplish the zero transverse shear stresses over the surface of the plate. Thus a need of shear correction factor is obviated. The present zigzag models able to meet the transverse shear stress continuity and zigzag form of in-plane displacement continuity at the plate interfaces. An efficient eight noded C° continuous isoparametric serendipity element is established and employed to examine the buckling analysis. Like FSDT, the considered mathematical model possesses similar number of variables and which decides the present models computationally more effective. Several numerical examples are carried out to study the effects of span to thickness ratio, ply orientation, lay-up number, modular ratio, loading condition and boundary condition on the buckling response. To ensure the capability of the proposed models, higher modes of buckling are obtained for laminated plates and sandwich plates. Further, the efficiency and superiority of the proposed models is ascertained by comparing it with 3 D elasticity solution and also with various existing shear deformation theories in the literature. Most remarkably, the present models are accurately estimates the buckling load parameter and they are insensitive of shear-locking.

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