ICNRE 2018
International Conference on Nanomaterials and Renewable Energies, 15-17 October 2018. Skikda, Algeria
Proposition of a mechanical model to predict the behaviour of a laminate bio composite material
D. Zelmatia,b*, O. Guelloudja,b, K. Bedouda, M. Hassania
a Research Center in Industrial Technologies (CRTI), P.O. Box 64, Cheraga 16014 Algiers, Algeria,
b LRTAPM: Research Laboratory of Advanced Technology in Mechanical Production, Department of Mechanical Engineering, Faculty of Engineering Science, Badji Mokhtar University Annaba, BP 12,
23000 Annaba, Algeria
*E-mail: zelmati_djamel@yahoo.fr
Keywords: Bio-composite, laminate, flax, modeling
Introduction: The purpose of this paper is to develop a mechanical model able to predict the mechanical behaviour of a laminate bio-composite material reinforced by the flax fibres without necessity to the expensive experimental test. A numerical comparative modelling based on finite element method is conducted by using in one hand a several stacking sequences, and in the other hand a growing plies number in order to estimate the lateral deflexion U3 in each plies of the bio- composite subjected to compression load. Meanwhile, the proposed mathematical model can be used as a power tool decision in design and the ensuring of the structure integrity.
The industrial actual tendency is to fabricate structures from materials with low cost in order to reduce the price and in the same time keeping the good quality without any structure oversizing. So, the laminate composite materials reinforced by vegetal fibres became the best alternative to the conventional materials exposed to the same loading. This latter is a potential parameter for the design and maintenance program in addition to fibres orientation or to several stacking sequences and the optimization of the laminate plies number [1, 2].
Description of the Work: In this study the geometrical model is a square plate of 200mm*200mm of a laminate Bio-composite material reinforced by flax fibres. Despite the different plate configurations, the wall thickness is fixed and equal to 5mm and the plate is subjected to the compression loading of 100MPa. Table 1 presents some properties of flax fibres in relation to those of E-glass [3, 4].
Table 1: Properties of flax fibres in relation to those of E-glass [3, 4]
Properties E-glass Flax Unity
Density 2.55 1.4 g/cm3
Tensile strength 2400 800-1500 MPa
E-Modulus 73 60-80 GPa
Specific (E/d) 29 26-46 /
Elongation at failure (%) 3 1.2-1.6 /
Moisture absorption (%) / 7 /
A 2D numerical simulation based on Abaqus code Vs 11 is conducted in order to assess the lateral deflection of the bio-composite reinforced by the flax fibres. Figure 1a and 1b shows respectively the boundary conditions and the meshing of the quarter of the plate. Figure 2 trend shows the evolution of the lateral deflection of the bio-composite material as a function of the plies number.
ICNRE 2018
International Conference on Nanomaterials and Renewable Energies, 15-17 October 2018. Skikda, Algeria
Figure 1: (a) boundary condition of the bio-composite (b) 2D meshing
Figure 2 Effect of the plies number on the lateral deflection u3 of the bio-composite flax/epoxy
Conclusion:
- The maximum deflection is recorded at the minimum plies number
- The plies number of the bio-composites represent a significant factor to pdidict the structure behaviour to the compression loading.
- For the bio-composite configuration of 0/30°, the plies umber is optimized to be 30 plies.
- A mechanical model is developed to predict the lateral deflection as a function of the plies number and the angle orientation
References
[1] Tsai, S.W. and Hahn, H.T., Introduction to Composite Materials, CRC Press, Boca Raton, FL, Table 1.7, p. 19; Table 7.1, p. 292; Table 8.3, p. 344.
[2] Mechanics of fibrous composites, Mahmood HuseinDatoo, Elsevier, (1991)
[3] Wambua, Paul, Jan Ivens, and Ignaas Verpoest. Comp. Sci. Tech 63.9 (2003) 1259-1264
[4] Beukers A. In: Van Hinte, editor. Lightness, the inevitable renaissance of minimum energy structures. Rotterdam: 010 publishers; 1999. p. 72
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