TMMOB Metalurji ve Malzeme Mühendisleri Odas ı E ğ itim Merkezi Bildiriler Kitab ı 749 19. Uluslararas ı Metalurji ve Malzeme Kongresi | IMMC 2018 Characterization of Cactus Nopal Natural Fiber as Potential Reinforcement of Epoxy Composites: Mechanical and Vibration Analysis Errouane Lahouaria, Kasdali Hafsa, Deghoul Nadjia, Merzoug Abdelrezak, Boussoufi Aicha Laboratoire Structure De Composite et Matériaux innovants. Département de Génie Maritime, Faculté de Génie mécanique, BP 1505 El M’naouer, USTO, Oran, Algérie Abstract In this work, we presented a dynamic analysis of a canoe paddle made of natural plant fibers extracted from Cactus Nopal (prickly pear) and mixed with epoxy resin. The different methods of extracting Cactus fibers, as well as the mechanical characterization for the new stratified bio-composites are also established in this study. Three different fiber architectures were extracted. The samples and bio- composite paddles were subjected to static and dynamic mechanical tests to estimate their mechanical properties, the natural frequencies of these new building materials. 1. Introduction Nowadays, the integration of new ecological materials is a major necessity. Therefore, the use of plant fibers becomes more and more important for researchers. The interest for natural plant fibers resides in their specific properties, such as biodegradability, abundance, renewable character and low cost [1]. The use of vegetable fibers (wood, linen, hemp) as reinforcement elements in polymer, thermo-plastic or thermosetting materials, that usually use glass fibers, is an already industrialized and marketed concept [2]. The Nopal Cactus (or Barbary Fig) is plant species of the family Cactaceae, native to Mexico, and naturalized in other continents, including the Mediterranean area, South and North Africa. Opuntia ficus-indica or Opuntia joconostle are the most often breeding species in the Nopals family. The buffers of almost all Opuntia species are edible. However, the major obstacle to their use in so-called "structural" applications is the lack of knowledge of their behavior, their damage and their aging [3]. Some researches have already been done on this plant. The study presented by Noureddine Barka and al [4] shoed that dried cactus can be used as an effective alternative natural biosorbent in eliminating wastewater metals. They carried out biosorption experiments for the elimination of cadmium and lead ions from aqueous solutions with the help of dried cactus as a natural biosorbent. Their results showed that optimal biosorption can be achieved at pH 5.8 and 3.5 and that the biosorption capacity decreases when increasing the solution temperature. Roberto Castro-Munoz and al [5] found that a composite formed with cactus has low water content, freshwater activities, excellent solubility and high hygroscopicity. The microstructures generated are rigid structures due to the presence of gelatin. Physicochemical characteristics were determined in Opuntia ficus indica cactus by Lorena Pérez Méndez and al. [6]. They found that Opuntia cactus had high ash, absolutely insoluble fiber, pH, acidity, ascorbic acid, Na and Cu values were small. L. Guo and al. [7] experimentally studied the behavior of a single droplet of cactus spines on the conical spine for Newtonian and non-Newtonian fluids. While, Bouakba et al [8] studied the mechanical behavior of composite polyester / cactus fiber laminates in 3-point bending in static and fatigue. They also proposed a new fiber extraction technique consisting of burying snowshoes in the ground for 15 days. Burial favors the fermentation of calcium oxalate, which makes the fiber extraction easier. The work we have undertaken is within the framework of a canoe paddle is based on the natural Nopal cactus fiber. The aim is to improve the performance, quality and even the lifetime of the paddle. In this study it was proposed to realize this new method as a fast, simple, and effective for production of green paddles with enhanced mechanical properties. 2. Extraction of cactus fibers type Nopal Three different fiber architectures were identified from the extraction process, corresponding to three different parts of the cactus trunk. The plant fibers of nopal cactus are extracted by different methods. The method used in this study combines the three most used extraction methods, namely are biological extraction, steam exposure and the chemical process. Figure 1. Nopal cactus plant.
Transcript
TMMOB Metalurj i ve Malzeme Mühendisleri Odas ı Eğ i t im MerkeziBildir i ler Kitab ı
74919. Uluslararas ı Metalurj i ve Malzeme Kongresi | IMMC 2018
Characterization of Cactus Nopal Natural Fiber as Potential Reinforcement of Epoxy Composites: Mechanical and Vibration Analysis
Laboratoire Structure De Composite et Matériaux innovants. Département de Génie Maritime, Faculté de Génie mécanique, BP 1505 El M’naouer, USTO, Oran, Algérie
Abstract
In this work, we presented a dynamic analysis of a canoe paddle made of natural plant fibers extracted from Cactus Nopal (prickly pear) and mixed with epoxy resin. The different methods of extracting Cactus fibers, as well as the mechanical characterization for the new stratified bio-composites are also established in this study. Three different fiber architectures were extracted. The samples and bio-composite paddles were subjected to static and dynamic mechanical tests to estimate their mechanical properties, the natural frequencies of these new building materials.
1. Introduction
Nowadays, the integration of new ecological materials is a major necessity. Therefore, the use of plant fibers becomes more and more important for researchers. The interest for natural plant fibers resides in their specific properties, such as biodegradability, abundance, renewable character and low cost [1]. The use of vegetable fibers (wood, linen, hemp) as reinforcement elements in polymer, thermo-plastic or thermosetting materials, that usually use glass fibers, is an already industrialized and marketed concept [2]. The Nopal Cactus (or Barbary Fig) is plant species of the family Cactaceae, native to Mexico, and naturalized in other continents, including the Mediterranean area, South and North Africa. Opuntia ficus-indica or Opuntia joconostle are the most often breeding species in the Nopals family. The buffers of almost all Opuntia species are edible. However, the major obstacle to their use in so-called "structural" applications is the lack of knowledge of their behavior, their damage and their aging [3]. Some researches have already been done on this plant. The study presented by Noureddine Barka and al [4] shoed that dried cactus can be used as an effective alternative natural biosorbent in eliminating wastewater metals. They carried out biosorption experiments for the elimination of cadmium and lead ions from aqueous solutions with the help of dried cactus as a natural biosorbent. Their results showed that optimal biosorption can be achieved at pH 5.8 and 3.5 and that the biosorption capacity decreases when increasing the
solution temperature. Roberto Castro-Munoz and al [5] found that a composite formed with cactus has low water content, freshwater activities, excellent solubility and high hygroscopicity. The microstructures generated are rigid structures due to the presence of gelatin. Physicochemical characteristics were determined in Opuntia ficus indica cactus by Lorena Pérez Méndez and al. [6]. They found that Opuntia cactus had high ash, absolutely insoluble fiber, pH, acidity, ascorbic acid, Na and Cu values were small. L. Guo and al. [7] experimentally studied the behavior of a single droplet of cactus spines on the conical spine for Newtonian and non-Newtonian fluids. While, Bouakba et al [8] studied the mechanical behavior of composite polyester / cactus fiber laminates in 3-point bending in static and fatigue. They also proposed a new fiber extraction technique consisting of burying snowshoes in the ground for 15 days. Burial favors the fermentation of calcium oxalate, which makes the fiber extraction easier. The work we have undertaken is within the framework of a canoe paddle is based on the natural Nopal cactus fiber. The aim is to improve the performance, quality and even the lifetime of the paddle. In this study it was proposed to realize this new method as a fast, simple, and effective for production of green paddles with enhanced mechanical properties.
2. Extraction of cactus fibers type Nopal
Three different fiber architectures were identified from the extraction process, corresponding to three different parts of the cactus trunk. The plant fibers of nopal cactus are extracted by different methods. The method used in this study combines the three most used extraction methods, namely are biological extraction, steam exposure and the chemical process.
Figure 1. Nopal cactus plant.
UCTEA Chamber of Metallurgical & Materials Engineers’s Training Center Proceedings Book
750 IMMC 2018 | 19th International Metallurgy & Materials Congress
The method consists of burying the trunk in soil with less than 30 cm of depth (without sand). During the 45 days (in dry weather, with average temperature of 27 ° C) the fermentation of calcium oxalate was achieved and thus the extraction of the cactus fiber layers facilitated. The fibers were then washed with water and air-dried with external exposure for at least two days (average T = 27 ° C and 25% humidity). Figure 2 shows the cross-sectional view of nopal cactus snowshoes after 45 days and before rinsing with water.
Figure 2. Rinsing Nopal Cactus Fibers and Drying to Air After 45 Days of Landfilling (Prior to Water
Rinsing).
From Figure 2 we can observe that the extracted cactus fibers from the trunk are localized in the middle and on the former extremities. The fibers were extracted from an old trunk (about 26 years old). The changes in architecture as a result of its maturation is shown in Figure 3.
Figure. 3 Architecture of the cactus fibers nopal according to its maturation.
3. Mechanical tensile test
3.1 The matrix
The tensile tests were carried out using epoxy matrix (NEXANS, type ISM 45G). The specimens were made in rectangular shape in accordance with NF EN ISO 527-1 standard using universal machine equipped with force sensor and extensometer, and applying load speed of 20 mm / min. The dimensions of the samples were 250 x 25 x 5 mm.
Figure 4 illustrates the stress-strain curves of five samples tested. An approximation of results is observed for all the specimens. From the three-zone curves, the first linear zone shows low strain with low stress. The second zone, which is the plastic and the most dominant zone, rather large stress with a high
deformation can be observed. While, the third zone shows the point at which the test piece breaks. This indicates that the behavior of NEXANS epoxy resin (type ISM 45G) has a ductile behavior.
0 1 2 3 4 5 6 7 80
2
4
6
8
10
12
14
16
Ep 1 Ep 2 Ep 3 Ep 4 Ep 5
Stre
ss
Strain [%]
Figure 4. Tensile stress-strain curve of the epoxy matrix NEXANS ISM 45 G.
Table 1 summarizes the tensile mechanical characteristics of all the specimens of the ISM 45G matrix. The average moderated Young's modulus of the matrix is of the order 211.047 MPa, with a tensile strength of 12.80 MPa and a strain of about 34.14%.
Table 1 Tensile mechanical characteristics of the NEXANS ISM45G epoxy matrix.
3.2 Nopal cactus fibers
In this study, three basic architectures cactus fibers were studied and their mechanical behavior was determined by estimating the Young's modulus, tensile strength and deformation. These fiber architectures were selected from different locations of the cactus trunk. Architecture No. 1 corresponds to the fibers extracted from the inner core of the trunk (Figure 5.a), while Architecture No. 2 are the fibers belonging to the median section (Figure 5.b), and architecture No. 3 to the outer core (Figure 5.c).
a) Architecture No.1 b) Architecture No.2 c) Architecture No.3 Figure 5. Three configurations of nopal cactus fiber
specimen.
Specimen S [mm2] rup [Mpa]
rup % E [Mpa]
Epr 1 121.44 12.59 15.93 228.503
Epr 2 118.75 11.20 73.46 101.679
Epr 3 114.41 13.28 32 146.831
Epr 4 118.59 13.90 26.66 284.571
Epr 5 97.05 13.02 26.66 293.652
Average 12.80 34.14 211.047
TMMOB Metalurj i ve Malzeme Mühendisleri Odas ı Eğ i t im MerkeziBildir i ler Kitab ı
75119. Uluslararas ı Metalurj i ve Malzeme Kongresi | IMMC 2018
On Figure 6, we can see that the fibers have almost the same behavior and almost the same pace. The stress-strain curves of all three samples consists of three parts. The first very short initial part represents linear behavior, the second part is related to the stiffening effect due to the alignment of the fibrils and finally a final softening (relief) behavior is observed before the total breaking of the fibers. According to the results obtained from the evolution of stress-strain curves for the loading of uni-axial traction, the architecture of the cactus fibers with a very dense mesh (No.3) presents the best mechanical behavior compared to the other two samples (open mesh and a medium mesh),.
0 1 2 3 4 5 60,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
Stre
ss
Strain
Ep 1 Open mesh Ep 2 Average mesh Ep 3 Dense mesh
Figure 6. Comparison of the stress-strain curves between the 3 architectures of the nopal cactus fibers.
Although the specimens are cut from the same plate, the results obtained from the stress, deformation and Young Module are characterized by dispersions between the different specimens tested. The origin of these observed dispersions for the Young's modulus is due to the strong anisotropy of the fibers and can be related to the fraction of volume of fibers, which is an uncontrollable factor taking into account the morphology of the cactus tissue. While the dispersion in stress and strain values can be directly atributed to the cavities of the matrix and the variety of fiber architecture.
Table 2 Mechanical tensile properties of the nopal cactus fiber for each architecture
3.3 Nopal / Epoxy Cactus Composites
The composite specimens were prepared using cactus fibers (Architecture No. 2 and No. 3) and epoxy resin. The specimens were cut in the direction of the fibers with dimensions of l = 250 mm length, b = 25 mm width and e = 2.5 mm thickness (according to the AFNOR 57-101 standard).
0 1 2 3 4 5 6 7 8 9 100,0
2,5
5,0
7,5
10,0
12,5
15,0
17,5
Stress
[N
/mm2
]
Strain
Ep 1 (Open mesh) Ep 2 (Average mesh) Ep 3 (Average mesh) Ep 4 (Dense mesh) EP 5 (Dense mesh)
Figure 7. Comparison of stress-strain curves for the two cases of composites studied.
The same findings were noted for the stress-strain curves shown in Figure 7. The longitudinal modulus was calculated with a slope between (0.5 to 1) % of the deformation. The obtained characteristics are presented in Table 3.
Table 3 Mechanical characteristics tensile composite fiber / resin of the two architectures.
4. Mechanical characterization of fiber cactus nopal / epoxy in 3 point bending
Three-point bending tests were performed to determine the deflection and flexural modulus. A very important increase in the breaking force value and the displacement for the cactus fibers of a dense mesh was observed. From these results, can be noted that the bending is strongly linked to the variation of the fiber architectures in particular in the vicinity of the central area, i.e. low fiber areas in the tested samples. The dispersion observed is generally related to the anisotropy of the fiber (Figure 8).
5. Canoe Paddling by Nopal Cactus and Epoxy Resin Fibers
This study proposes to build a canoe paddle based on a natural Nopal cactus fiber as a fast, simple, and effective tool for paddling and canoeing.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 150
20
40
60
80
100
120
140
Force
[N]
Deflection [mm]
Ep1 Average mesh Ep2 Average mesh Ep3 Average mesh Ep4 Average mesh
a) Architecture N° 02
Architecture Max [N/mm2]
rup % E [MPa]
Architecture 1 0.167 3.73 72.8
Architecture 2 0.369 2.66 160.64
Architecture 3 1.012 4.73 279.38
Specimens S [mm2] max [Mpa]
rup % E [Mpa]
Arch2 Epr 1 111.66 11.07 8.8 253.879
Epr 2 136.20 11.06 5.8 206.484
Epr 3 120.02 13.24 8.4 213.708
Arch3 Epr 1 113.01 17.17 4.4 421.389
Epr 2 120.97 13.88 4.5 317.585
Average Arch2 max [Mpa]
11.79 E[Mpa]
224.69
Arch3 max [Mpa]
15.525 E[Mpa]
369.48
UCTEA Chamber of Metallurgical & Materials Engineers’s Training Center Proceedings Book
752 IMMC 2018 | 19th International Metallurgy & Materials Congress
b) Architecture N° 03Figure 8. Force-deflection of the 3-point bending test
on Arch 02 and Arch 03 fibers.
6 . Vibration analysis of the paddle Nopal cactus fibers
The experimental analysis was carried out in the case of bending of the structure. The paddle in the first place is free on both sides, and then clamped at one end and free at the other.
6.1 Free-Free The frequency response of the paddles are plotted in Figure 11. We can observe 6 peaks (eigenfrequencies) of different Amplutide, such as a rapid decrease of amplutide after the 4th frequency. These results include torsion modes as well as bending modes. Precisely, modes 2 to 4 are bending modes. There is a wide gap between the three frequencies. The other modes correspond to the torsion modes.
Figure 9. Nopal cactus fiber paddle
Figure10. Frequency response of the paddle "torsion and flexion" free - free.
6.1 Clamped-Free
Figure 12 shows the Fourier transform of the impulse excitation response of the cactus fiber paddle. This response shows peaks corresponding to the natural frequencies of the vibrations of our structure. The curve
gives six natural frequencies of different amplitudes. By comparison, we note that always the first 3 modes are related to flexural modes.
Figure 11. Frequency response of the paddle "bending frequency" clamped _ free.
7. Conclusion
From the results obtained, we can conclude that:
The tensile behavior of the three architectures of the nopal cactus fibers are not identical when different fiber architectures are used;
The fibers of a dense mesh "architecture 03" are more resistant and behave better than other architectures;
Significant and very appreciable frequencies were observed during vibration testing of the paddle cactus / epoxide;
Each natural frequency corresponds to a specific mode of the deformation of the system.
References
[1] M. E. BOURAHLI. Mémoire du doctorat, thèse «
université Farhat Abbas setif 1. [2] Al-Kaabi, A. Al-Khanbashi. Date Palm Fibers as Polymeric Matrix Reinforcement:DPF/Polyester. Composite Properties, polymer composites, (2005), pp.604-613 [3] E. Mohamed Structure and morphology of cladodes and spines of Opuntia cus-indica. Cellulose extraction and characterisation. A Centre de Recherches sur les Macromole ´cules Ve ´ge t́ales (CERMAV-CNRS), [4] N. Barka, M. Abdennouri, M. El Makhfouk, S. Qourzal. Biosorption characteristics of cadmium and lead onto eco-friendly dried cactus (Opuntia ficus indica) cladodes. Journal of Environmental Chemical Engineering 1 (2013) 144 149. [5] C. M. Roberto, E. Blanca H. Barragan, J.Y. Fernandez. Use of gelatin-maltodextrin composite as an encapsulation support for clarified juice from purple cactus pear (Opuntia
- Food Science and Technology 62 (2015) 242e248. [6] L. Pérez Méndez, F.T. Flores, J. D. Martín, E. M. Rodríguez Rodríguez, C. D. Romero. Physicochemical characterization of cactus pads from
188 (2015) 393 398. [7] L. Guo, G.H. Tang. Experimental study on directional
Journal of Heat and Mass Transfer 84 (2015) 198 202 [8] M. Bouakba, A. Bezazi, K. Boba , F. Scarpa, S. Bellamy.Cactus fibre/polyester biocomposites Manufacturing, quasi-static mechanical and fatigue characterization. Composites Science and Technology 74 (2013) 150 159.
