STRUCTURAL ANALYSIS OF AIRCRAFT WINGS MADE OF NATURAL FIBER REINFORCED COMPOSITESS

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 11, November 2018, pp , Article ID: IJMET_09_ Available online at aeme.com/ijmet/issues.asp?jtype=ijmet&vtype= =9&IType=11 ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed STRUCTURAL ANALYSIS OF AIRCRAFT WINGS MADE OF NATURAL FIBER REINFORCED COMPOSITESS D. Aravind Kumar, G. Gokul Raj, G. Shivaani and V.M. Sreehari School of Mechanical Engineering, SASTRAA Deemed to be University, Thanjavur, India ABSTRACT Composites play a major role in the present day automobile and aerospace industries. Natural fibers can be used instead of synthetic fibers as the reinforcing elements mainly because of their eco-friendly nature. In recent years, researchers are conducting more studies on natural fiber reinforced composite because of their advantages like biodegradability, low density, and cost effectiveness compared to the synthetic fiberrein forced composites. Bending, buckling, and vibration analysis of an aircraft wing made of natural fiber reinforced composites have been explored in the present study. Natural fibers like sisal, flax, aloevera fibers reinforced in epoxy matrix are used as inner layers. Glass epoxy and graphite epoxy were used as outer layers. ANSYS Mechanical APDL software has been employed for analyzing aircraft wing made of natural fiber reinforced composites in present work. Keyword: Natural fiber reinforced composites, Aircraft wing, Bending, Buckling, and Vibration. Cite this Article: D. Aravind Kumar, G. Gokul Raj, G. Shivaani and V.M. Sreehari, Structural Analysis of Aircraft Wings Made of Natural Fiber Reinforced Composites, International Journal of Mechanical Engineering and Technology, 9(11), 2018, pp IType=11 1. INTRODUCTION Study on natural fiber reinforced composites (NFRC) is a significant area of research as natural fibers act as reinforcement and provides the required stiffness, and it is preferred for many applications due to strict environment policies. They have low cost, density and weight. They result only less pollution during manufacturing causing only minimal health risks and are thus eco-friendly in nature. The physical properties are comparable to synthetic fibers. At present, most of the automobile companies are employing natural fiber composites fordoorlining, sound proofing material, paneling, interiors, seat cushioning. The aircraft indoor structures also can be made from NFRCs. The agro waste composite materials are eco editor@iaeme.com

2 D. Aravind Kumar, G. Gokul Raj, G. Shivaani and V.M. Sreehari friendly, economically fit as well as disposable materials. Common fibers such as flax, sisal, aloevera, hemp are often applied as the reinforcement of composite. In the wing structure also composite plays a major role, along with aluminium, fiber glass. To test by the composite material, the test starts with small scale model and then with the larger parts of the aircraft and followed by full structure. Several articles are available on the composite structure responses [1-3]. Miravete [4] measured the resin impregnation and prediction of fabric properties where it is on the textile reinforcements in the composite materials. Valadez et al. [5] studied the effect fiber surface treatment on the fiber matrix bond strength of NFRCs. Oksman et al. [6] observed that the flax fibers and polylactic acid has been used for biodegradable products, but polylactic acid can also be employed as a binding material in composites. Thomas et al.[7] studied the behavior of a NFRC beam made up of aloevera fibers. Frederick and Norman [8] highlighted the growing interest in the development of novel materials which improvebestuse of natural resources and particularly of renewable resources. O'Donnell et al. [9] discussed in detail about the natural fiber composite with the plant oil based resin. Few authors [10, 11] have discussed the physical and chemical properties of natural fibers. Mo et al. [12] observed that the usage of biomass can also reduce global warming compared with fossil fuels and the challenges for the future on the utilization of biomass reinforcements in the manufacturing of composites. Toldy et al. [13] studied in the biodegradability and eco-friendly behaviour of the natural fibers. Nagendra et al. [14] calculated the structural responses using the ANSYS software. Balakrishnan et al. [15] noted that the natural fibers have low density and low weight.ganesh et al. [16] explained that instead of using of carbon fibers natural fibers can be useddue to their non-hazardous, bio degradable, low cost and availability, with less density and weight. Thus the area of present discussion is very relevant. 2. METHODOLOGY The aircraft wing made of NFRC is developed using ANSYS Mechanical APDL. Initially the aircraft wing is developed and then bending, buckling and vibration analysis were done. Before creating the model some parameters like material properties of natural fiber reinforced composites are to be known. By using these values (as in Table 1) we can form the aircraft wings which are made up of sisal, flax, aloevera, glass and graphite epoxy. In this model 20 layered composite wing is created. Top and bottom 2 layers out of the 20 layers are graphite epoxy or glass epoxy and in between 16 layers are sisal, flax, oraloevera epoxy. Table 1 Material properties Material E 1 E 2 E 3 Poisson s ratio G 1 G 2 G 3 Sisal epoxy Flax epoxy Aleovera epoxy Firstly, preferences (Structural) has to be chosen and then preprocessing has to be performed. There the element type (Brick 8 node 45) is chosen. The key points for creating airfoil are considered as (0, 0, 0), (0.25, 0.05, 0), (0.25, -0.05, 0), (0.75, 0.1, 0), (0.75, -0.1, 0), (1, 0, 0). By extruding the airfoil it will become as an aircraft wing. Figure 1 shows the aircraft wing. The aircraft wing has a dimension of span length of 7m, chord length of 1 m, and tmax of 0.1 m. After preprocessing the main job is to mesh the wing. Element edge length is given as The wing is completely meshed. The next important step is to give load to editor@iaeme.com

3 Structural Analysis of Aircraft Wings Made of Natural Fiber Reinforced Composites the aircraft wing. A cantilever beam condition, that is one end fixed and other end free is considered. All degree of freedom are constrained at fixed end. Load of 1000N is given in upward direction. Figure 2 clearly show the loads acting in an aircraft wing as the conditions mentioned above. Different type of structural responses like bending, buckling, and vibration can be analyzed in solution step. By solving current LS, the solution of the analysis is obtained. Using general post processing we can take the results of bending, buckling and vibration in contour plot. The results are discussed in below section. Figure 1 Aircraft wing Figure 2 Loads acting in a wing 3. RESULTS AND DISCUSSIONS The results for bending, buckling and vibration of an aircraft wing made of NFRC is presented in this section. In the initial bending analysis, top and bottom 2 layers are graphite epoxy and in between 16 layers are of different NFRC like sisal, flax, aloevera epoxy. Then analysis with top and bottom 2 layers of glass epoxy and in between 16 layers of different NFRC like sisal, flax, aloevera epoxy is performed. Thus maximum displacement for 6 cases is noted and the deformed shapes are observed. Similar analysis is conducted for buckling and vibration. The buckling factor and frequency values for the 6 cases as mentioned above are noted. Figure [3,4] shows the bending analysis results for NFRC s with outer layers as graphite, and glass epoxy. From the figure we can get maximum displacement value. Figure [5,6] shows the results for buckling analysis for NFRC s with outer layers as graphite, and glass epoxy. From these figures the value of buckling factors can be noted. Figure [7,8] shows the results for vibration analysis for NFRC s with outer layers as graphite, and glass epoxy. From these figures the value of natural frequencies can be noted. Figure 3 Bending of composite wing having sisal, flax, and aloevera epoxy inner layers and graphite editor@iaeme.com

4 D. Aravind Kumar, G. Gokul Raj, G. Shivaani and V.M. Sreehari Figure 4 Bending of composite wing having sisal, flax, and aloevera epoxy inner layers and glass Figure 5 Buckling of composite wing having sisal, flax, and aloevera epoxy inner layers and graphite Figure 6 Buckling of composite wing having sisal, flax, and aloevera epoxy inner layers and glass editor@iaeme.com

5 Structural Analysis of Aircraft Wings Made of Natural Fiber Reinforced Composites Figure 7 Vibration of composite wing having sisal, flax, and aloevera epoxy inner layers and graphite Figure 8 Vibration of composite wing having sisal, flax, and aloevera epoxy inner layers and glass Table 2 Structural responses of composite wing having sisal, flax, and aloevera epoxy inner layers and graphite NFRC used for inner layers Maximum displacement (mm) Buckling factor Natural frequency(hz) Sisal epoxy Flax epoxy Aloevera epoxy editor@iaeme.com

6 D. Aravind Kumar, G. Gokul Raj, G. Shivaani and V.M. Sreehari Table 3 Structural responses of composite wing having sisal, flax, and aloevera epoxy inner layers and glass NFRC used for inner layers Maximum displacement (mm) Buckling factor Natural frequency(hz) Sisal epoxy Flax epoxy Aloevera epoxy The results from Figures 3-8 are concluded in Tables 2-3. From the Table 2 it can be observed that the maximum displacement value will be very less for composite wing composed of flax epoxy when compared to sisal, aloevera epoxy for the same loading conditions. As the maximum displacement value is less, it can be concluded that structural strength of wing is made of flax epoxy is high compared to wings made of other NFRC. Also it is noticed that composite wing composed of flax epoxy has highest buckling factor, implying it can withstand high loads compared to others and has the best structural stability. In case of vibration analysis it is noted that composite wing composed of flax epoxy has high natural frequency, so that structure will have good vibration characteristics. Similar nature of structural responses were observed for composite wing composed of NFRC with glass epoxy outer layers as presented in the Table 3. By analysing the structural responses presented in above tables for graphite or glass epoxy with combination of NFRC, optimum material that can be used in aircraftwing, can be chosen. Such wings made of NFRC can be applied in small robotic aircrafts, MAV s, etc. 4. CONCLUSIONS An aircraft wing made up of NFRC was analysed for its bending, buckling, and vibration behaviour. The characteristics of aircraft wing made up of NFRC when it undergone loading are presented in detail. Compared to synthetic fibers NFRC s are having low cost, low density, low weight, easily biodegradable, and ecofriendly in nature. Two different combinations has been analyzed, i.e., one with top and bottom 2 layers of graphite epoxy and in between 16 layers are NFRC; and another is top and bottom 2 of glass epoxy and in between 16 are NFRC. Generally our consideration is to have a less displacement value, high natural frequency, and high buckling factor. By analyzing the results it can be concluded that flax epoxy composite is satisfying all the above conditions in both the cases. So it is suggested to have either graphite or glass as top and bottom layer for strength and to avoid environmental effects and should have other inner layers of flax epoxy and it can be widely applied in structural design of small robotic aircrafts, MAV s, etc editor@iaeme.com

7 Structural Analysis of Aircraft Wings Made of Natural Fiber Reinforced Composites REFERENCES [1] Jones R.M, Mechanics of composites, Material Science and Engineering Series.2nd Edition, Taylor & Francis [2] Sreehari V.M, Maiti D.K, Buckling and post buckling analysis of laminated composite plates in hygrothermal environment using an inverse hyperbolic shear deformation theory, Composite Structures129, 2015, pp [3] Sreehari V.M, Ravi Kumar B, Maiti D.K, Structural Analysis Using Shear Deformation Theories Having Nonpolynomial Nature: A Review, International Journal of Applied Engineering Research12 (20), [4] Miravete, Antonio, ed. 3-D textile reinforcements in composite materials. Woodhead Publishing, [5] Valadez-Gonzalez, A., et al. Chemical modification of henequen fibers with an organosilane coupling agent. Composites Part B: Engineering, 30.3, 1999, pp [6] Oksman, Kristiina, Mikael Skrifvars, and J-F. Selin. Natural fibres as reinforcement in polylactic acid (PLA) composites. Composites science and technology, 63.9, 2003, pp [7] Thomas P, Jenarthanan M.P, and Sreehari V.M, Free vibration analysis of a composite reinforced with natural fibers employing finite element and experimental techniques, Journal of Natural Fibers DOI: / [8] Frederick, T. W., and W. Norman. Natural fibers plastics and composites. EUA: KluwerAcademic Publishers, [9] O'donnell, A., M. A. Dweib, and R. P. Wool. Natural fiber composites with plant oilbased resin. Composites science and technology, 64.9, 2004, pp [10] Atagur, Metehan, and M. OzgurSeydibeyoglu, Fiber Technology for Fiber-Reinforced Composites, 1400, 2017, pp [11] Hinrichsen, Georg, et al. Natural Fibers, Biopolymers, and Biocomposites: An Introduction. Natural Fibers, Biopolymers, and Biocomposites, CRC Press, 2005, pp [12] Mo, X., D. Wang, and X. S. Sun. Straw-based biomass and biocomposites. Natural fibers, biopolymers, and biocomposites. Boca Raton: Crc Press-Taylor & Francis Group, 2005, pp [13] Toldy, A., B. Szolnoki, and Gy Marosi. Flame retardancy of fibre-reinforced epoxy resin composites for aerospace applications. Polymer Degradation and Stability, 96.3, 2011, pp [14] Nagendra Singh, Nagendra Kumar Maurya, and Rakesh Kumar Yadav. Linear buckling analysis of laminated composite plate. International journal of engineeringscience & Advanced Technology, 2.4, 2012, [15] Balakrishnan, P., et al. Natural fibre and polymer matrix composites and their applications in aerospace engineering. Advanced composite materials for aerospace engineering, 2016,pp [16] Ganesh R., Rajashekar Patil, and Narayan Nayak. Experimental Study on Mechanical Properties of Natural Fiber Reinforced Polymer Composite Materials for Wind TurbineBlades. Materials Today: Proceedings, 5.1, 2018, pp editor@iaeme.com