scholarly journals Linear Buckling Behaviour of Composite Laminate [(Θ/-Θ)] with Various Shaped Cutout using Fem

2019 ◽  
Vol 9 (1S4) ◽  
pp. 18-22
Keyword(s):  
Uniaxial Compression ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Buckling Load ◽  
Laminated Plate ◽  
Vertical Rectangle ◽  
Buckling Behavior ◽  
Linear Buckling ◽  
Polyester Composite ◽  
Layer Orientation

In this paper, the buckling behavior has been investigated on square laminate made of Woven-glass-polyester composite with various shaped cutouts (i.e., circle, square, vertical rectangle, horizontal rectangle, vertical ellipse, horizontal ellipse) numerically. The composite laminates have been arranged in asymmetrical order as [(θ/-θ)]. The laminated plate that is subjected to uniaxial compression has been emphasized on the laminate along with the effect of layer orientation, effect of cutout ratio and effect of cutout angle. The result shows that the minimum buckling load is obtained at 45° and the maximum buckling load attained at 0° and 90°for all laminates by increasing the layer orientation. For cutout ratio, the maximum and minimum load is obtained for the smallest and largest cutout ratio in all cutout shapes. Increasing the cutout angle, the square cutout exhibits the minimum load at 60°. In elliptical cutouts, the load is decreasing and increasing gradually while they are aligned in along and perpendicular to the loading directions. The rectangular cutouts positioned vertically and horizontally the load is decreasing up to 30° and 60°and then increasing up to 90°.

Critical buckling load of composite laminates containing delamination using differential quadrature method and ABAQUS finite element

2021 ◽  
pp. 030932472199657
Author(s):  
Hamed Edalati ◽  
Vahid Daghigh ◽  
Kamran Nikbin
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Differential Quadrature Method ◽  
Compressive Load ◽  
Differential Quadrature ◽  
Buckling Load ◽  
Quadrature Method ◽  
Critical Buckling Load ◽  
Finite Element Package

Differential quadrature method (DQM) was used to compute the critical buckling load (CBL) of composite laminates containing complex delamination shapes. The composite laminate was initially flat; however, it buckled under a compressive load due to weak adhesive between the outer ply and the whole composite laminate. Previous data obtained for composite laminates containing circular or elliptical delaminations by finite element and the Rayleigh-Ritz methods as well as DQM available in the literature were used to validate the accuracy of the approach. A good agreement between the results was observed. To show the ability of this approach for calculating the CBL of a composite laminate containing complex delamination shape, a crescent-shaped delamination was considered. The CBLs for various stacking sequences of such a composite laminate were then calculated and discussed. The commercial finite element package, ABAQUS was used to validate the DQM results for crescent delamination.

BUCKLING BEHAVIOR OF COMPOSITE LAMINATES (WITH AND WITHOUT CUTOUTS) SUBJECTED TO NONUNIFORM IN-PLANE LOADS

2013 ◽  
Vol 13 (08) ◽  
pp. 1350044 ◽  
Author(s):  
GANESH SONI ◽  
RAMESH SINGH ◽  
MIRA MITRA
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Structural Instability ◽  
Shear Load ◽  
Premature Failure ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Nonuniform Load ◽  
Parametric Studies ◽  
Plate Aspect Ratio

Critical buckling loads of composite laminates are usually calculated using analytical solutions based on the assumption of uniform in-plane loads, despite of the fact that real structures are often subjected to various nonuniform loads. The present work is focused on the buckling behavior of composite laminates, with and without cutouts, subjected to various nonuniform in-plane loads. The effect of the size of the cutouts, on the buckling behavior, has been studied using finite element method. Furthermore, parametric studies on the effects of plate aspect ratio, location of the cutout and the application of a nonuniform load combined with a shear load have also been studied. Higher buckling loads were observed in pure in-plane bending compared to uniformly/nonuniformly distributed loads. Consequently, it is important to consider nonuniformly distributed loading whenever applicable, to utilize complete strength of the composite laminate and to avoid premature failure of the composite laminate due to structural instability.

SELF-HEALING OF WOVEN COMPOSITE LAMINATES VIA IN SITU THERMAL REMENDING

2021 ◽  
Author(s):  
ALEXANDER D. SNYDER ◽  
ZACHARY J. PHILLIPS ◽  
JASON F. PATRICK
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Laminated Composites ◽  
Reaction Times ◽  
Carbon Fiber Composites ◽  
Self Healing ◽  
Damage Mode ◽  
Woven Composite ◽  
Internal Damage

Fiber-reinforced polymer composites are attractive structural materials due to their high specific strength/stiffness and excellent corrosion resistance. However, the lack of through-thickness reinforcement in laminated composites creates inherent susceptibility to fiber-matrix debonding, i.e., interlaminar delamination. This internal damage mode has proven difficult to detect and nearly impossible to repair via conventional methods, and therefore, remains a significant factor limiting the reliability of composite laminates in lightweight structures. Thus, novel approaches for mitigation (e.g., self-healing) of this incessant damage mode are of tremendous interest. Self-healing strategies involving sequestration of reactive liquids, i.e. microcapsule and microvascular systems, show promise for the extending service- life of laminated composites. However, limited heal cycles, long reaction times (hours/days), and variable stability of chemical agents under changing environmental conditions remain formidable research challenges. Intrinsic self- healing approaches that utilize reversible bonds in the host material circumvent many of these limitations and offer the potential for unlimited heal cycles. Here we detail the development of an intrinsic self-healing woven composite laminate based on thermally-induced dynamic bond re-association of 3D-printed polymer interlayers. In contrast to prior work, self-repair of the laminate occurs in situ and below the glass-transition temperature of the epoxy matrix, and maintains >85% of the elastic modulus during healing. This new platform has been deployed in both glass and carbon-fiber composites, demonstrating application versatility. Remarkably, up to 20 rapid (minute-scale) self-healing cycles have been achieved with healing efficiencies hovering 100% of the interlayer toughened (4-5x) composite laminate. This latest self-healing advancement exhibits unprecedented potential for perpetual in-service repair along with material multi-functionality (e.g., deicing ability) to meet modern application demands.

Damage Control in Composite Laminates

2001 ◽  
Author(s):  
Alexander P. Suvorov ◽  
George J. Dvorak
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Damage Control ◽  
Thermomechanical Loading ◽  
Interlaminar Stresses ◽  
Damage Resistance ◽  
Viscoelastic Composite ◽  
Mechanical Loads ◽  
Composite Damage ◽  
The Matrix

Abstract Several effects that fiber prestress may have on stress redistribution in the plies of composite laminates and in the phases of individual plies are illustrated. These include improvement of composite damage resistance under tensile mechanical loads, reduction/cancelation of interlaminar stresses at free edges of composite laminate subjected to thermomechanical loading, and stress relaxation in the matrix phase of viscoelastic composite laminates. Specific results are found for quasi-isotropic and cross-ply symmetric S-glass/epoxy and carbon/epoxy AS4/EPON 828 laminates.

THE EFFECT OF LAMINATION SCHEME AND ANGLE VARIATIONS TO THE DISPLACEMENTS AND FAILURE BEHAVIOUR OF COMPOSITE LAMINATE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Azizul Hakim Samsudin ◽  
Jamaluddin Mahmud
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Finite Element Modelling ◽  
Composite Laminate ◽  
Maximum Stress ◽  
Failure Load ◽  
Failure Criteria ◽  
Stress Theory ◽  
Failure Behaviour ◽  
Failure Index

This paper aims to investigate the effect of lamination scheme and angle variations to the displacements and failure behaviour of composite laminate. Finite element modelling and analysis of symmetric, anti-symmetric and angle-ply Graphite/ Epoxy laminate with various angles of fiber orientation subjected to uniaxial tension are performed. Maximum Stress Theory and Tsai-Wu Failure Criteria are employed to determine the failure load (failure index = 1). Prior to that, convergence analysis and numerical validation are carried out. Displacements and failure behaviour of the composite laminates (symmetric, anti-symmetric and angle ply) are analysed. The failure curves (FPF and LPF) for both theories (Maximum Stress Theory and Tsai-Wu) are plotted and found to be very close to each other. Therefore, it can be concluded that the current study is useful and significant to the displacements and failure behaviour of composite laminate.

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