Numerical and Experimental Characterization of the Dynamic Properties of Flax Fiber Reinforced Composites

In this paper, the damping properties of flax fiber reinforced composites were investigated. Throughout a series of resonance vibration tests, the natural frequencies and the modal damping were evaluated. A numerical modelling was also produced by using a finite element model to determine the energies dissipated in each layer of the laminate structure in order to calculate the damping factors. The results obtained for the dynamic properties of flax fiber reinforced composites from experimental data and numerical analysis method show close agreement. The effect of fiber orientations on the damping behavior for this material was investigated. Another part of our work was to insert a thin viscoelastic layer within the flax fiber laminate. The interposition of this viscoelastic layer had a significant influence on the vibration behavior, bending stiffness and damping factors.

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Vibration Behavior of Composite Material with Two Overlapping Delaminations

International Journal of Applied Mechanics ◽

10.1142/s1758825115500544 ◽

2015 ◽

Vol 07 (04) ◽

pp. 1550054 ◽

Cited By ~ 4

Author(s):

Maroua Hammami ◽

Abderrahim El Mahi ◽

Chafik Karra ◽

Mohamed Haddar

Keyword(s):

Natural Frequencies ◽

Fiber Reinforced Composites ◽

Reinforced Composites ◽

Fiber Reinforced ◽

Element Analysis ◽

Vibration Behavior ◽

Glass Fiber Reinforced ◽

Modal Damping ◽

Vibration Tests ◽

Vibration Parameters

The paper presents an analysis of the vibration behavior of glass fiber reinforced composites with two overlapping delaminations. The effect of delamination length on the vibration parameters is studied. Throughout a series of vibration tests, the change of natural frequencies and modal damping due to delaminations is evaluated. A numerical simulation considering finite element analysis allows to predict the change of natural frequencies for a known damage size. Modal damping was established which evaluates the different energies dissipated in the material layers direction of the fiber reinforced composites. A comparison of the different results was performed. Next, strain energy of layers directions were established by a numerical analysis and discussed.

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Damage mechanisms characterization of flax fibers–reinforced composites with interleaved natural viscoelastic layer using acoustic emission analysis

Journal of Composite Materials ◽

10.1177/0021998319836236 ◽

2019 ◽

Vol 53 (18) ◽

pp. 2623-2637 ◽

Cited By ~ 4

Author(s):

Abderrahim El Mahi ◽

Hajer Daoud ◽

Jean-Luc Rebiere ◽

Isabelle Gimenez ◽

Mohamed Taktak ◽

...

Keyword(s):

Acoustic Emission ◽

Mechanical Behavior ◽

Flax Fiber ◽

Fiber Reinforced Composites ◽

Viscoelastic Layer ◽

Uniaxial Tensile ◽

Reinforced Composites ◽

Fiber Reinforced ◽

Viscoelastic Composite ◽

The Impact

In this paper, the static and fatigue behavior of flax fiber-reinforced composites with and without an interleaved natural viscoelastic layer are investigated. Viscoelastic composite plates consist of a soft natural viscoelastic layer which is confined between two identical flax fiber reinforced composites. Different stacking sequences of specimens are tested with uniaxial tensile loading until failure. The mechanical behavior and the acoustic activity of damage sources in various configurations with and without a viscoelastic layer are compared. The analysis of acoustic emission signals and the macroscopic and microscopic observations led to the identification of the main acoustic signatures of different damage modes dominant in each type of composites (with and without a viscoelastic layer). These results allow better identification of the influence of the impact of a viscoelastic layer on the mechanical behavior of different composites. In addition, static and fatigue flexural behavior of unidirectional composites with and without viscoelastic layer are characterized in 3-point bending tests. The effects of viscoelastic layer on the stiffness, hysteresis loops, and loss factor are studied for various numbers of cycles during cyclic fatigue.

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