The effect of multi-directional stiffness degradation on the non-linear analysis of composite laminates

2012 ◽  
Vol 19 (2) ◽  
pp. 127-137
Author(s):  
Sung-Cheon Han ◽  
Won-Hong Lee ◽  
Weon-Tae Park
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Shell Element ◽  
Linear Analysis ◽  
Matrix Cracking ◽  
Stiffness Degradation ◽  
Non Linear ◽  
Directional Stiffness

AbstractA formulation of element-based Lagrangian 9-node shell element based modified first-order shear deformation theory is improved for non-linear behaviors of composite laminates containing matrix cracking. Using the refined ANS (assumed natural strain) shell elements either show the optimum combination of sampling points with an excellent accuracy or remove the locking phenomenon. The multi-directional stiffness degradation caused by matrix cracking, which was proposed by Duan and Yao, is conducted. Natural coordinate based higher-order transverse shear strains are used in the present shell element. Numerical examples demonstrate that the present element behaves reasonably satisfactorily either for the linear or geometrical non-linear analysis of laminated composite structures. The results of laminated composite shells with matrix cracking may be the benchmark test for the non-linear analysis of damaged composite laminates.

Inelastic finite element analysis of fibre-reinforced composite laminates with damage

1998 ◽  
Vol 212 (8) ◽  
pp. 717-729
Author(s):  
C L Chow ◽  
F Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Laminates ◽  
Composite Structures ◽  
Laminated Composite ◽  
Equilibrium Equations ◽  
Element Analysis ◽  
Finite Element Program ◽  
Reinforced Composite ◽  
Non Linear

In this study, a method of finite element analysis is presented to examine the three-dimensional inelastic behaviour of fibre-reinforced composite laminates with damage. The constitutive model for the characterization of mechanical responses of non-linear composite materials to damage that was proposed recently by the authors is employed. The formulation of the elastic damage stress-strain relationship in incremental form is first developed and then incorporated within the context of the displacement-based finite element procedure. Solution of the non-linear equilibrium equations is obtained with the modified Newton—Raphson iteration technique. Numerical implementation of the stress calculation is discussed in detail. Results predicted using the present finite element program for uniaxial off-axis tensile loading of unidirectional graphite/epoxy composite laminates show satisfactory agreement with those obtained from experiments. Other results describing the development of damage zones, the inelastic effect on stress distributions and material property variations due to damage in cross-ply laminated composite structures are also examined and discussed.

scholarly journals Non-linear deflection and stress analysis of laminated composite sandwich plate with elliptical cutout under different transverse loadings in hygro-thermal environment

2020 ◽  
Vol 7 (1) ◽  
pp. 80-100
Author(s):  
Rahul Kumar ◽  
Achchhe Lal ◽  
B. M. Sutaria
Keyword(s):  
Stress Concentration ◽  
Sandwich Plate ◽  
Thermal Environment ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Gauss Point ◽  
Composite Sandwich ◽  
Aspect Ratios ◽  
Present Solution ◽  
Non Linear

AbstractIn this paper, non-linear transverse deflection, stress and stress concentration factors (SCF) of isotropic and laminated composite sandwich plate (LCSP) with and without elliptical cutouts subjected to various trans-verse loadings in hygrothermal environment are studied. The basic formulation is based on secant function-based shear deformation theory (SFSDT) with von-Karman nonlinearity. The governing equation of non-linear deflection is derived using C0 finite element method (FEM) through minimum potential energy approach. Normalized trans-verse maximum deflections (NTMD) along with stress concentration factor is determined by using Newton’s Raphson method through Gauss point stress extrapolation. Influence of fiber orientations, load parameters, fiber volume fractions, plate span to thickness ratios, aspect ratios, thickness of core and face, position of core, boundary conditions, environmental conditions and types of transverse loading in MATLAB R2015a environment are examined. The numerical results using present solution methodology are verified with the results available in the literatures.

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