A. Elayaperumal

Banana Fiber Reinforced Polymer Composites - A Review

This paper presents a summary of research work published in the field of banana fiber reinforced polymer composites with special references to the structure, physical and mechanical properties of the composites.

Mechanical and water absorption properties of woven jute/banana hybrid composites

This work aims to predict the mechanical properties of woven jute/banana hybrid composite. Woven fabrics are arranged in three layers of different sequence. Resin used in this work is Epoxy LY556 with hardener HY951. Composite specimen are prepared by hand-layup techniques. The effect of layering sequence on the mechanical properties namely tensile, flexural and impact was analysed. It is found that the tensile and flexural strength of hybrid composite (Banana/Jute/Banana) is higher than that of individual composites. Similarly, the impact strength of Jute/Banana/Jute hybrid composite is better than other types of composite. It is found that the moisture absorption of woven banana fiber composite is lesser than the hybrid composite. Fractography study of the fractured specimen is carried out using scanning electron microscope to analyse the fracture behaviour of the hybrid composite.

Effect of fiber length and fiber content on mechanical properties of banana fiber/epoxy composite

The main factors that influence the properties of composite are fiber length and content. Hence the prediction of optimum fiber length and content becomes important, so that composite can be prepared with best mechanical properties. Experiments are carried out as per ASTM standards to find the mechanical properties namely, tensile strength and modulus, flexural strength and modulus, and impact strength. In addition to mechanical properties, water absorption capacity of the composite is also studied. Further, fractured surface of the specimen are subjected to morphological study using scanning electron microscope. The investigation revealed the suitability of banana fiber as an effective reinforcement in epoxy matrix.

Hole quality evaluation of natural fiber composite using image analysis technique

The natural fiber-reinforced composites are emerging as a possible replacement to glass fiber composite for low-cost applications. Of the various machining process, drilling is one of the most common machining processes used for the assemblage of various parts. During drilling process, composites undergo delamination phenomenon that reduces the structural reliability of the component. The present work focuses on the analysis of delamination behaviour as a function of drilling process parameters at the entrance and exit of the composite plates. In this work, drilling was carried out by varying the feed (0.1, 0.2, 0.3 mm/rev) and speed (500, 1000, 1500 and 2000 r/min), respectively. The drill bit used is made of high-speed steel of a diameter of 10 mm. The quality of the hole drilled was assessed using the machine vision technique, and the extent of delamination was carried out using the ultrasonic C-scan imaging method. The experimentally observed delamination factor was compared with ANOVA technique and found that the feed rate affect the delamination than speed. A correlation between the parameters of interest was carried out using multi-variable linear regression analysis technique.

Mode I Fracture Toughness of Banana Fiber and Glass Fiber Reinforced Composites

Although fiber-reinforced polymers (FRP) have until now been largely applied to various fields of engineering, these materials have also been used in many technical applications, especially where high strength and stiffness are required, but with low component weight. Among various natural fibers, banana fiber is of particular interest in that its composites have high tensile strength, high tensile modulus, and low elongation at break beside its low cost and eases of availability. In this study, banana fiber and glass fiber reinforced polyester Resin composites were prepared using hand lay up technique . Experiments are conducted to compare and to find the effect of fiber volume fraction on mode I fracture toughness of both composites.

Wear Characteristics of Al 6061 Reinforced with Graphite under Different Loads and Speeds

This work investigates Al 6061 alloy with graphite particle impregnated metal matrix composites under dry sliding conditions. The conventional casting techniques were used for preparing the composite material. Experiments were conducted under dry sliding conditions for determining the wear behavior of Al 6061 alloy- Graphite composite material with varying wt % graphite content under different sliding speeds and at different loads. Sliding distance of 250m was commonly used for the wear test. A pin on disc machine was used for conducting the wear test. The test was conducted under atmospheric conditions. Wear rate decreases with increased sliding speed and increases with increasing load. Worn surfaces of the composites were examined through scanning electron microscope. The wear loss of the composite material with 5Wt % graphite was found to be minimum with respect to sliding speeds and loads.

Drillability study of pultruded and sheet moulding compound thick polymeric composites

This article discusses the effects of process parameters (feed and spindle speed) on quality characteristics (thrust force, torque, surface roughness and ovality) for standard and special geometric design of a drill body in dry drilling of pultruded and sheet moulding compound thick composites. Pultruded (non-laminated) and sheet moulding compound (laminated) thick glass fibre–reinforced plastic composites with a higher percentage of fibre weight fraction are extensively used in construction of bridges, prefabricated platforms, ballistic applications, structural applications, instrument bases and automotive load floors, and therefore, prediction of better performance drill helps the fabrication industry in making good quality holes. The drilling experiments using coated tungsten carbide drills, twist drill (standard geometry) and ratio drill (special geometry) of diameter of 10 mm were conducted using response surface methodology. Analysis of variance of the experimental results reveals that for both twist drill and ratio drill, feed is more significant in influencing the quality characteristics. The experimental values obtained for quality characteristics are empirically related to process parameters by developing response surface models using Design-Expert software. Analysis of the experimental results reveals that ratio drill performs better in pultruded composites and twist drill performs better in sheet moulding compound composites. The optimal process parameter levels within the selected range for minimizing all the quality characteristics together were determined.

Micro/Nanostructure and Tribological Characteristics of Pressureless Sintered Carbon Nanotubes Reinforced Aluminium Matrix Composites

This study reports the manufacture, microstructure, and tribological behaviour of carbon nanotube reinforced aluminium composites against pure aluminium. The specimens were fabricated using powder metallurgy method. The nanotubes in weight percentages of 0.5, 1.0, 1.5, and 2.0 were homogeneously dispersed and mechanically alloyed using a high energy ball milling. The milled powders were cold compacted and then isothermally sintered in air. The density of all samples was measured using Archimedes method and all had a relative density between 92.22% and 97.74%. Vickers hardness increased with increasing CNT fraction up to 1.5 wt% and then reduced. The microstructures and surfaces were investigated using high resolution scanning electron microscope SEM. The tribological tests showed that the CNT reinforced composites displayed lower wear rate and friction coefficient compared to the pure aluminium under mild wear conditions. However, for severe wear conditions, the CNT reinforced composites exhibited higher friction coefficient and wear rate compared to the pure aluminium. It was also found that the friction and wear behaviour of CNT reinforced composites is significantly dependent on the applied load and there is a critical load beyond which CNTs could have adverse impact on the wear resistance of aluminium.

Drying and energy aspects of tapioca sago processing-an experimental field study

The drying characteristics of tapioca sago were studied using four different drying methods—Open sun drying (OSD), Conveyor belt drying (CBD), Bin drying (BD) and Fluidized bed drying (FBD)—in an industry located in Tamilnadu, India (Latitude: 11.494347° N; Longitude: 78.272264° E). The BD and FBD dryers were designed and fabricated as pilot scale models in the laboratory with respective capacity of 5 kg/h and 10 kg/h; CBD (1000 kg/h) and OSD are the commercial drying operations currently employed in industrial processing. The drying time, energy and exergy aspects of all the drying methods were compared along with the achieved final moisture content, color and quality of the dried products. The highest Energy utilization ratio (EUR) was found in CBD and FBD in the range of 20-76 % and 10-67 %, respectively. The exergy efficiency was initially low in all the cases but increased to 80 % towards the end of the drying process.

Influence of SMA reinforcement on the impact resistance of GFRP composite laminates under different temperatures

Plain glass fibre-reinforced polymeric (GFRP) laminates and GFRP reinforced with randomly oriented short strips of shape memory alloy (SMA) were prepared by hand lay-up method. The SMA strip reinforcement was placed at 0.75 × thickness of the laminate with weight fractions of 2, 4 and 6%. The specimens were exposed to drop weight impact test and the experiments were conducted at a constant impact velocity of 2.80 m s−1 with different test temperatures such as 303, 333 and 363 K. The impact damage area was evaluated using lighting technique and fracture response was analysed using scanning electron microscopic (SEM) images. Absorption of impact energy and damage area due to low velocity impact were calculated. It was observed that with the higher temperature, the SMA/GFRP laminates exhibit marginally-enhanced damage resistance compared to the plain GFRP laminates. Also, addition of SMA reinforcement was not contributing much to the impact resistance at higher temperature.