Effect of Shear Lag on Buckling Behavior of Hat Shaped Laminated Composite Box Sections

2019 ◽  
pp. 445-453
Author(s):  
K. C. Praseeja ◽  
Nithin Mohan
Keyword(s):  
Laminated Composite ◽  
Shear Lag ◽  
Buckling Behavior

A Damage Model Containing Delamination in Composite Laminates

2006 ◽  
Vol 324-325 ◽  
pp. 43-46
Author(s):  
Yu Pu Ma ◽  
Xin Zhi Lin ◽  
Qing Fen Li ◽  
Zhen Li
Keyword(s):  
Composite Laminates ◽  
Damage Model ◽  
Laminated Composite ◽  
Shear Lag ◽  
Analysis Model ◽  
Transverse Cracks ◽  
Transverse Cracking ◽  
Stiffness Reduction ◽  
Laminated Composite Materials ◽  
Modulus Reduction

When stress is high, delaminate damage can be induced by transverse cracks. A complete parabolic shear-lag damage model containing delamination induced by transverse cracks is therefore proposed and applied to predict the stiffness reduction by transverse cracking in cross-ply laminated composite materials. The predictions of the complete parabolic shear-lag analysis model, the incomplete parabolic shear-lag analysis model, and the complete parabolic shear-lag damage model containing delamination proposed in this paper have been compared. Results show that the young’s modulus reduction values obtained by our analysis model are better agreement with the experimental ones than other models.

Influence of Crack on the Instability of GFRP Composite Cylindrical Shells under Combined Loading

2018 ◽  
Vol 877 ◽  
pp. 453-459
Author(s):  
B. Angelina Catherine ◽  
R.S. Priyadarsini
Keyword(s):  
Structural Integrity ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
External Pressure ◽  
Industrial Applications ◽  
Combined Loading ◽  
Finite Element Software ◽  
Buckling Behavior ◽  
Thin Walled ◽  
Composite Cylindrical Shells

Buckling is a prominent condition of instability caused to a shell structure as a result of axial loadings. The process of buckling becomes more complex while analyzing thin walled structures like shells. Today such thin walled laminated composite shells are gaining more importance in many defense and industrial applications since they have greater structural efficiency and performance in relation to isotropic structures. Comprehensive understanding of the buckling response of shell structures is necessary to assure the integrity of these shells during their service life. The presence of defects, such as cracks, may severely compromise their buckling behavior and jeopardize the structural integrity. This work aims in conducting numerical analysis of cracked GFRP (Glass fibre-reinforced polymer) composite cylindrical shells under combined loading to study the effect of crack size on the buckling behavior of laminated composite cylindrical shells with different lay-up sequences. The numerical analyses were carried out using the finite element software, ABAQUS in order to predict the buckling behaviour of cracked laminated composite cylinders subject to different combinations of axial compression, torsion, internal pressure and external pressure from the interaction buckling curves.

Modeling the Effective Elastic Behavior of a Transversely Cracked Laminated Composite

1998 ◽  
Vol 120 (1) ◽  
pp. 191-198
Author(s):  
D. J. Thomas ◽  
R. C. Wetherhold
Keyword(s):  
Laminated Composite ◽  
Point Of View ◽  
Crack Spacing ◽  
Elastic Behavior ◽  
Shear Lag ◽  
Underlying Assumption ◽  
Shear Lag Model ◽  
Matrix Cracks ◽  
State Present ◽  
Lag Model

The solution for the stress state present in the vicinity of transverse matrix cracks within a composite laminate is typically obtained by assuming a regular crack spacing geometry for the problem and applying a shear-lag analysis. In order to explore the validity of this underlying assumption, the probability density function for the location of the next transverse matrix crack within a crack bounded region is examined. The regular crack spacing assumption is shown to be reasonable from an engineering point of view. Continuing with this assumption, a generalized shear-lag model for multilayer, off-axis laminates subjected to full in-plane loads is developed. This model is used to quantitatively evaluate the effective elastic properties of the damaged material. The results are applicable to materials such as ceramic matrix or polymer matrix unidirectional fiber systems where damage in the form of transverse matrix cracks arises.

scholarly journals Thermal Buckling of Laminated Composite Plates Using a Simple Four Variable Plate Theory

2021 ◽  
Vol 27 (9) ◽  
pp. 1-19
Author(s):  
Hussein Tawfeeq Yahea ◽  
Wedad Ibraheem Majeed
Keyword(s):  
Plate Theory ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Thermal Buckling ◽  
Design Parameters ◽  
Laminated Composite Plates ◽  
Buckling Behavior ◽  
Uniform Temperature Field

In this study, the thermal buckling behavior of composite laminate plates cross-ply and angle-ply all edged simply supported subjected to a uniform temperature field is investigated, using a simple trigonometric shear deformation theory. Four unknown variables are involved in the theory, and satisfied the zero traction boundary condition on the surface without using shear correction factors, Hamilton's principle is used to derive equations of  motion depending on a Simple Four Variable Plate Theory for cross-ply and angle-ply, and then solved through Navier's double trigonometric sequence, to obtain critical buckling temperature for laminated composite plates. Effect of changing some design parameters such as, orthotropy ratio (E1/E2), aspect ratio (a/b),  thickness ratio (a/h), thermal expansion coefficient ratio (α2/α1), are investigated, which have the same behavior and good agreement when compared with previously published results with maximum discrepancy (0.5%).

Buckling analysis of anti-symmetric cross and angle-ply laminated composite plates

2018 ◽  
Vol 106 (2) ◽  
pp. 205
Author(s):  
L. Bouyaya
Keyword(s):  
Plate Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Longitudinal Direction ◽  
Laminated Plates ◽  
Buckling Load ◽  
Governing Equations ◽  
Navier Solution ◽  
Buckling Behavior ◽  
Important Progress

This article has for objective to analyze the buckling behavior of the unidirectional laminated plates. In this purpose, we propose an analytically method, based on the theory of classical, orthotropic plate theory. The governing equations are solved using Navier solution for uniform uniaxial loading in longitudinal direction. We were interested to identify the critical buckling load for simply supported antisymmetric cross-ply and antisymmetric angle-ply laminates of rectangular shape. Some important progress has been made on these relatively complicated buckling problems, involving coupling between bending and midplane stretching during a buckling deformation. Effects of different parameters such as fiber orientation angles, aspect ratio, modular ratio and number of layers were examined. Results are presented in the form of plots showing the variation in non-dimensional buckling load.

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