Experimental and Numerical Studies on Natural Fibres Reinforced Polymer Composites Gundumalla Krishna 1, Pinjarla Poorna Mohan 2

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1 Experimental and Numerical Studies on Natural Fibres Reinforced Polymer Composites Gundumalla Krishna 1, Pinjarla Poorna Mohan 2 1 M. Tech Student, 2 Sr.Assistant Professor 1,2 Department of Mechanical Engineering, Godavari Institute of Engineering and Technology (Autonomous), Rajahmundry , Andhra Pradesh, India. g.krishna17@gmail.com 1, pinjarlapoornamohan@gmail.com 2 Abstract: These days composites are gaining upper hand over alloys and conventional materials like iron, copper, nickel, etc. Composites applications expanded not only to terrestrial products manufacturing s but also to the extra-terrestrial manufacturing industries like aerospace industries for building space stations, rockets, space shuttles, space pods, etc. This is due to their strength to weight ratio, good mechanical properties, thermal and electrical properties and their ability withstand the harsh operating environment, easy fabrication process, and low costs. The studies on natural fibre composites are getting the attention of researchers because they can be best alternative reinforcements for fibre composites due to their non- abrasive nature, their availability and economic feasibility. The natural fibre reinforced composite is best for ecology as they are degradable being eco- friendly. In this studies abundantly available natural fibres like banana, jute, coconut fibres,and husk granules are taken as reinforcements and mixed with AW11 resin and HW 953 IN hardener to form composite test specimens. Thus formed composite test specimens, BFRC (Banana Fibre Reinforced Composite), CFRC (Coconut Fibre Reinforced Composite), HGRC (Husk Granule Reinforced Composite) and JFRC (Jute Fibre Reinforced Composite) are tested on UTM (Universal Testing Machine) for evaluating mechanical properties. The stress-strain curves, stress concentration factors and buckling are described by numerical methods. Keywords: BFRC, CFRC, HGRC, JFRC, AW11, HW 953 IN, Resin, Hardener, Composite, UTM I. INTRODUCTION Because of environmental conditions and environment manageability issues, this century has seen wonderful accomplishments in green innovation in the field of materials science through the improvement of biocomposites. The advancement of these elite materials produced using natural assets is expanding around the world. The greatest challenge in working with natural fiber reinforced composites is their extensive variety of properties and qualities. A biocomposite's properties are influenced by various factors, including the type of fiber selected as reinforcement, natural conditions (where the plant fibers are sourced), preparing techniques, and any modification of the fiber. It is likewise realized that as of late there has been a surge of interest for the modern uses of composites containing biofibers reinforced with biopolymers. Biopolymers have seen an enormous increment being used as a matrix for biofiber reinforced composites. There is a developing pattern to utilize biofibers as fillers as well as reinforcers in plastics composites. Their flexibility amid preparing, profoundly specific stiffness, and low cost (on a volumetric premise) make them attractive to producers. This century has seen consistently expanding requests for the use of plastics as essential crude materials, over 7% of which are thermoplastics. Biofiber strengthened plastic composites are increasing and increasingly acknowledged in structural applications. This paper expects to do more research on current reinforcement of natural fibers in polymer composites polymer composites. This paper won't address regular fibers from creatures (e.g., silk or fleece) or cotton or man-made cellulosic fibers. This work additionally rejects wood fiber or flour. In this studies abundantly available natural fibres like banana, jute, coconut fibres,and husk granules are taken as reinforcements and mixed with AW11 resin and HW 953 IN hardener to form composite 372

2 test specimens. Thus formed composite test specimens, BFRC (Banana Fibre Reinforced Composite), CFRC (Coconut Fibre Reinforced Composite), HGRC (Husk Granule Reinforced Composite) and JFRC (Jute Fibre Reinforced Composite) are tested on UTM (Universal Testing Machine) for evaluating mechanical properties. The stress-strain curves and stress concentration factors are described by numerical methods. II. MATERIAL PROPERTIES The test specimens used as a part of the study will have the 3D geometry which resembles the rectangular prism. The dimension of the specimen such as length, width, and height are used to calculate the diagonals of the prism, areas, and volume. Figure 1 shows the basic geometry of the test specimens on which the test specimens are prepared. Figure 1: Basic Geometry of test samples The test specimens are prepared by using open casting technique. The test specimens dimensions are shown in Table 1. Dimensions Diagonals Areas Height Width Length Side Top End Internal Side Top End Total mm mm Mm mm mm mm mm mm 2 mm 2 mm 2 mm Table 1 III. FABRICATION AND TESTING A. BFRC Preparation: The test specimens of varying heights, 6 mm, 8 mm and 1 mm are made using banana fibre stands as reinforcement and AW 11 resin and HV 953 IN hardener as a matrix to form BRRC. The finally open casted specimens are shown in figure

3 Fig 2: BRRC specimens of heights 6 mm, 8 mm and 1 mm B. CFRC Preparation: The test specimens of varying heights, 6 mm, 8 mm and 1 mm are made using coconut fibres in rope pattern as reinforcement and AW 11 resin and HV 953 IN hardener as a matrix to form BRRC. The open casting of specimen samples is shown in figure 3. The finally open casted specimens are shown in figure 4. Fig 3: CFRC Specimen open casting Fig 4: CFRC specimens of heights 6 mm, 8 mm and 1 mm C. HGRC Preparation: The test specimens of varying heights, 6 mm, 8 mm and 1 mm are made using husk granules as reinforcement and AW 11 resin and HV 953 IN hardener as a matrix to form BRRC. The open casting of specimen samples is shown in figure 5. The finally open casted specimens are shown in figure 6. Fig 5: HGRC Specimen open casting 374

4 Fig 6: HGRC specimens of heights 6 mm, 8 mm and 1 mm D. JFRC Preparation: The test specimens of varying heights, 6 mm, 8 mm and 1 mm are made using jute fibres in plain weave pattern as reinforcement and AW 11 resin and HV 953 IN hardener as a matrix to form BRRC. The open casting of specimen samples is shown in figure 7. The finally open casted specimens are shown in figure8. Fig 7: JFRC Specimen open casting Fig 8: JFRC specimens of heights 6 mm, 8 mm and 1 mm The BFRC, CFRC, HGRC and JFRC samples made by using open casting techniques and using banana fibres, husk granules, coconut fibres and jute fibres as reinforcement materials and resin AW 11 and hardener HV 953 IN as matrix materials are tested on Universal Testing Machine (UTM). Testing Procedure: The test pieces of BFRC, CFRC, HGRC and JFRC samples are taken and one at a time and fixed between the two chucks of the UTM as shown in figure 9. The machine is then turned on to conduct tension test. The loading on the test piece starts from KN and goes on increasing till the test pieces get failed. The process is repeated for all the 12 test specimen samples. Then the loads and percentage elongation values reflect on the output monitor. These values are taken and the Young s Modulus, Ultimate Strength, Percentage Elongation and Yield Strength for the specimen are calculated numerically. 375

5 Fig 9: JFRC Specimen Thus, the materials are tested experimentally to obtain the results such as Young's modulus, ultimate strength, percentage elongation and yield strength for evaluating the specimen samples both experimentally and numerically. IV. EXPERIMENTAL RESULTS 1. Results of tensile testing of specimen: A. BFRC Specimen Test Result: The BFRC specimen samples with 6 mm, 8 mm and 1 mm heights are tested in UTM by performing tensile testing. The material loading and deformation results are shown in Table 2. Fibres/Dimensions (H x W x L) Load (KN) Elongation (mm) BFRC 6 X 3 X BFRC 8 X 3 X BFRC 1 X 3 X Table 2 B. CFRC Specimen Test Result: The CFRC specimen samples with 6 mm, 8 mm and 1 mm heights are tested in UTM by performing tensile testing. The material loading and deformation results are shown in Table 3. Fibres/Dimensions (H x W x L) Load (KN) Elongation (mm) CFRC 6 X 3 X CFRC 8 X 3 X CFRC 1 X 3 X Table 3 C. HGRC Specimen Test Result: The HGRC specimen samples with 6 mm, 8 mm and 1 mm heights are tested in UTM by performing tensile testing. The material loading and deformation results are shown in Table 4. Fibres/Dimensions (H x W x L) Load (KN) Elongation (mm) HGRC 6 X 3 X HGRC 8 X 3 X

6 HGRC 1 X 3 X Table 4 E. JFRC Specimen Test Result: The JFRC specimen samples with 6 mm, 8 mm and 1 mm heights are tested in UTM by performing tensile testing. The material loading and deformation results are shown in Table Fibres/Dimensions (H x W x L) Load (KN) Elongation (mm) JFRC 6 X 3 X JFRC 8 X 3 X JFRC 1 X 3 X Table 5 2. Calculated results for specimen samples: The load (KN) values and elongation (mm) values of each sample are taken and are used in the calculation of the properties such asyoung's modulus, ultimate strength, percentage elongation and yield strength required for numerical analysis are calculated by using the equations of engineering mechanics only. TheYoung's modulus, ultimate strength, percentage elongation and yield strength calculated are tabulated in Table 6 and Table 7. Fibres Dimensions (H x W x L) Young s Modulus (GPa) Ultimate Tensile Strength (N/mm 2 ) BFRC 6 X 3 X BFRC 8 X 3 X BFRC 1 X 3 X CFRC 6 X 3 X CFRC 8 X 3 X CFRC 1 X 3 X HGRC 6 X 3 X HGRC 8 X 3 X HGRC 1 X 3 X JFRC 6 X 3 X JFRC 8 X 3 X JFRC 1 X 3 X Fibres Dimensions (H x W x L) Table 6 Yield Strength (N/mm 2 ) at Rapture (%) BFRC 6 X 3 X BFRC 8 X 3 X BFRC 1 X 3 X CFRC 6 X 3 X CFRC 8 X 3 X CFRC 1 X 3 X

7 Stress MPa International Journal of Scientific Research and Review HGRC 6 X 3 X HGRC 8 X 3 X HGRC 1 X 3 X JFRC 6 X 3 X JFRC 8 X 3 X JFRC 1 X 3 X Table 7 These values are used in stress-strain approximations and numerical evaluations. 1. Stress- Curve Approximations: V. NUMERICAL EVALUATIONS A. BFRC Stress Stain Curves: The BFRC specimen samples are evaluated numerically to obtain stress-strain curves. The plots are plotted in MS EXCEL from the obtained data after numerical analysis and are shown in the figure1, figure2, and figure3 for 6 mm, 8 mm and 1 mm height specimen samples Fig 1: Plot for BFRC 6 mm height sample

8 International Journal of Scientific Research and Review Fig2: Plot for BFRC 8 mm height sample Fig3: Plot for BFRC 1 mm height sample B. CFRC Stress Stain Curves: The CFRC specimen samples are evaluated numerically to obtain stress-strain curves. The plots are plotted in MS EXCEL from the obtained data after numerical analysis and are shown in the Fig4, Fig 5, and Fig6 for 6 mm, 8 mm and 1 mm height specimen samples Fig 4: Plot for CFRC 6 mm height sample

9 International Journal of Scientific Research and Review Fig 5: Plot for CFRC 8 mm height sample Fig6: Plot for CFRC 1 mm height sample C. HGRC Stress Stain Curves: The HGRC specimen samples are evaluated numerically to obtain stress-strain curves. The plots are plotted in MS EXCEL from the obtained data after numerical analysis and are shown in thegraph 7, Figure 5.8, and Figure 5.9 for 6 mm, 8 mm and 1 mm height specimen samples Fig 7: Plot for HGRC 6 mm height sample

10 International Journal of Scientific Research and Review Fig 5.8: Plot for HGRC 8 mm height sample Fig 5.9: Plot for HGRC 1 mm height sample D. JFRC Stress Stain Curves: The JFRC specimen samples are evaluated numerically to obtain stress-strain curves. The plots are plotted in MS EXCEL from the obtained data after numerical analysis and are shown in the Figure 5.1, Figure 5.11, and Figure 5.12 for 6 mm, 8 mm and 1 mm height specimen samples. The plot data is included in the appendix Fig 5.1: Plot for JFRC 6 mm height sample

11 Fig 5.11: Plot for JFRC 8 mm height sample Stress [MPa] Fig 5.12: Plot for JFRC 1 mm height sample 2 Stress Concentration Factors: Stress Concentration Factors: The BFRC, CFRC, HGRC and JFRC specimen samples are evaluated numerically to obtain stress concentration factor. The plots are plotted by use of MechaniCalc and are shown in the Graph 13 for three samples on condition, rectangular bar with forces, Figure 14, Figure 15, and Figure 16 for 6 mm, 8 mm and 1 mm height specimen samples on condition, rectangular bar with moments. The input details to calculate the stress concentration factors for case Rectangular bar with forces and Rectangular bar with moments for 6mm, 8mm and 1 mm thick specimen samples are tabulated in Table 8. Case Rectangular bar with forces Rectangular bar with moments Input values 6 mm 8 mm 1 mm w = 3 mm, d = 8 mm 6 mm 8 mm 1 mm w = 3 mm, d w = 3 mm, d w = 3 mm, d = 8 mm, = 8 mm, = 8 mm, t = 6 mm t = 8 mm t = 6 mm Table 8 The results to of stress concentration factors for case Rectangular bar with forces and Rectangular bar with moments for 6mm, 8mm and 1 mm thick specimen samples are tabulated in Table 9. Case Results Rectangular bar with forces 6 mm 8 mm 1 mm =.267, K t = 2.4 Rectangular bar with 6 mm 8 mm 1 mm 382

12 moments = =.267 K t = 1.74 = 1. =.267 K t = 1.82 =.8 =.267 K t = 1.88 Table 9 Fig 13: Plot for Rectangular bar with forces 6mm, 8 mm & 1 mm height sample Fig 14: Plot for Rectangular bar with moments 6 mm height sample Fig 15: Plot for Rectangular bar with moments 8 mm height sample 383

13 Fig 16: Plot for Rectangular bar with moments 1 mm height sample The results to of stress concentration factors specimen samples for case Rectangular bar with forces and Rectangular bar with moments for 6mm, 8mm and 1 mm thick specimen samples are all equal for BFRC, CFRC, HGRC and JFRC materials since the stress concentration factor is independent of the material used. These are the results of stress-strain approximation curves, and stress concentration factors obtained after carrying numerical evaluations the numerical evaluation on the BFRC, CFRC, HGRC and JFRC samples made by using open casting techniques and using banana fibres, husk granules, coconut fibres and jute fibres as reinforcement materials and resin AW 11 and hardener HV 953 IN as matrix materials. 3 STRESS STRAIN CURVES COMPARISON The stress-strain curves are compared for the BFRC, CFRC, HGRC and JFRC specimen samples made by using open casting techniques and using banana fibres, husk granules, coconut fibres and jute fibres as reinforcement materials and resin AW 11 and hardener HV 953 IN as matrix materials and are shown in the Figure 17 to Figure 23. Scatter plots are used for the comparison of specimen samples stress-strain curve samples. Figure 17 shows the scatter plot for BFRC specimen samples made up of 6mm, 8mm and 1 mm thickness. 7 BFRC 6 BFRC 8 BFRC (NA) 384

14 Fig 17: BFRC specimen Scatterplot Figure 18 shows the scatter plot for CFRC specimen samples made up of 6mm, 8mm and 1 mm thickness. 8 CFRC 6 CFRC 8 CFRC (NA) Fig 18: CFRC specimen Scatterplot Figure 19 shows the scatter plot for HGRC specimen samples made up of 6mm, 8mm and 1 mm thickness. Fig 19: HGRC specimen Scatterplot Figure 2 shows the scatter plot for JFRC specimen samples made up of 6 mm, 8 mm and 1 mm thickness. Fig 2: JFRC specimen Scatterplot 385

15 Figure 21 shows the scatter plot for comparison of the BFRC, CFRC, HGRC and JFRC specimen samples made up of 6 mm thickness. 1 BFRC 6 CFRC 6 HGRC 6 JFRC (NA) Fig 21: 6 mm thickness specimens Scatterplot Figure 22 shows the scatter plot for comparison of the BFRC, CFRC, HGRC and JFRC specimen samples made up of 8 mm thickness. 8 BFRC 8 CFRC 8 HGRC 8 JFRC (NA) Fig 22: 8 mm thickness specimens Scatterplot 386

16 Figure 23 shows the scatter plot for comparison of the BFRC, CFRC, HGRC and JFRC specimen samples made up of 1 mm thickness. Fig 23: 1 mm thickness specimens Scatterplot These are the comparison scatter plots of stress-strain approximation curves obtained after carrying numerical evaluations the numerical evaluation on the BFRC, CFRC, HGRC and JFRC samples made by using open casting techniques and using banana fibres, husk granules, coconut fibres and jute fibres as reinforcement materials and resin AW 11 and hardener HV 953 IN as matrix materials. VI. CONCLUSION The aim of the work to produce a cost-effective biodegradable composites using AW 11 epoxy and HV 953 IN hardener as matrix and banana fibres, husk granules, coconut fibres, and jute fibres in various weaving patterns to form BFRC, CFRC, HGRC and JFRC composites and to evaluate the materials both experimentally is done by conducting specimen tensile tests on UTM and using mathematical approach. The following are the yield stress values of the specimen samples on which the selection of the material for engineering applications are determined: i. BFRC specimen samples made by 6 mm, 8 mm and 1 mm thickness show yield stress values of 6.55 MPa, MPa, and 51.9 MPa. ii. CFRC specimen samples made by 6 mm, 8 mm and 1 mm thickness show yield stress values of MPa, MPa, and 6.3 MPa. iii. HGRC specimen samples made by 6 mm, 8 mm and 1 mm thickness show yield stress values of MPa, 77.5 MPa,and66.76 MPa. iv. JFRC specimen samples made by 6 mm, 8 mm and 1 mm thickness show yield stress values of MPa, MPa, and 59 MPa. All the specimen samples of BFRC, CFRC, HGRC and JFRC composites with 6 mm, 8 mm and 1 mm thickness shows a factor of safety values greater than.5 when analyzed numerically. From this we can conclude that these materials can be used for replacing non biodegradable materials such as plastics, metals, etc., in industrial applications or fabricating products or as construction materials where there is a material with same sustainability qualities are required. 387

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