Sivakumar Dhar Malingam

Selection of natural fibre reinforced composites using fuzzy VIKOR for car front hood

Weight reduction of transportation vehicles is an important method in improving fuel efficiency, reducing energy consumption and greenhouse gas emissions. One of the solutions is through the application of green materials as substitutes to conventional engineering materials. However, the selection of a suitable substitute material for the intended application often imposes great challenges due to the variety of alternative materials to choose from as well as the need to satisfy multiple and conflicting requirements from various stakeholders. Therefore, the aim of this study is to use fuzzy VIKOR, the multiple criteria decision making method, to identify the appropriate type of natural fibre for fibre reinforced composites to be applied on the fibre metal laminate for car front hood to achieve the transportation weight reduction. The result suggested that M3 (kenaf) has the best criteria. Kenaf has been selected as the best natural fibre as it satisfies two compromise solutions. It has a least VIKOR index value υ = 0.5. The results of the fuzzy VIKOR demonstrate the potential of natural fibre to be applied on the fibre metal laminate structure as a car front hood; this which could reduce vehicle weight and subsequently reduce the overall vehicle CO2 gas emissions.

Effect of Reprocessing Palm Fiber Composite on the Mechanical Properties

Concern for the environment, both in terms of limiting the use of finite resources and the need to manage waste disposal, has led to increasing pressure to recycle materials at the end of their useful life. This work describes the effects of reprocessing on the mechanical properties of oil palm fiber reinforced polypropylene composites (PFC). Composites, containing 30wt% fiber with 3wt% Maleate Polypropylene as a coupling agent, were reprocessed up to six times. For this composite, tensile strength (TS) and Young modulus (YM) were found to decrease by 9.6% and 4.7% after being reprocessed for six times. Flexural strength was found to decrease by 23.8% with increased number of reprocessing. The hardness numbers of the composite were found to increase by 7.43% from 72.10 to 77.89 after the sixth reprocessing. In general the degradation on the mechanical properties is considered to be small and PFC has potential to be reprocessed.

A review of the tensile and fatigue responses of cellulosic fibre-reinforced polymer composites

ABSTRACT The use of polymer-based composites has been gaining popularity in the industry over the last few decades. Their high strength to weight ratio and high fatigue resistance make these composites the preferred materials for a wide variety of applications. The current trend has inclined towards hybrid fibre reinforced composites owing to their outstanding characteristics compared to non-hybrid composites. Numerous research works have been conducted to study the fatigue life behaviour of such composite materials. This study addressed the monotonic and dynamic performance of non-hybrid and hybrid natural fibre based composite materials, and the factors that influence their fatigue performance, along with the stiffness decay of each composite material. Most studies have shown the superior potential of using natural fibres in place of synthetic fibres in those critical applications that involve tensile and cyclic loading.

Weighting Of Natural Fibre Criteria For Fibre Metal Laminate Using Entropy Method For Car Front Hood Utilization

Material selection is one of the crucial stages in design and development process which depend on various physical, mechanical and manufacturing properties. To increase the success probability of the product, the designer needs to decide the suitable material. Therefore, to increase the reliability of the product, entropy method could be applied to determine the importance of criteria for the material used. Entropy method is a highly reliable and can be adjusted to information measurement to determine weighting criteria in decision making environment. Weighting criteria of material play a very significant role in the ranking results of the material selection. Therefore, the aim of this study is to utilise entropy method to rank the main criteria of the natural fibre used in fibre metal laminate panel for car front hood design. It is important to define the main criteria of materials during the material selection process to prevent any mechanical failure and to control the raw material cost. Most of the fibre metal laminate in the market utilise synthetic fibre, while natural fibre is rarely explored. Entropy method was applied to determine the main criteria weighting of natural fibre using five criteria. The result showed the highest rank to the lowest rank for the main criteria is density, stiffness, water absorption, cost and finally availability.

Effect of formation temperature on properties of graphite/stannum composite for bipolar plate

Bipolar plates are key components in Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In this research, the raw materials used to fabricate the high performance bipolar plate are Graphite (Gr), Stannum (Sn) and Polypropylene (PP). All materials used was in powder form and Gr and Sn act as fillers and the PP acts as binder. The ratio of fillers (Gr/Sn) and binder (PP) was fixed at 80:20. For the multi-conductive filler, small amount of Sn, which is 10 up to 20wt% (from the total weight of fillers 80%) have been added into Gr/Sn/PP composite. The fillers were mixed by using the ball mill machine. The second stage of mixing process between the mixer of fillers and binder is also carried out by using ball mill machine before the compaction process by the hot press machine. The effect of formation temperatures (160°C-170°C) on the properties of Gr/Sn/PP composite had been studied in detail, especially the electrical conductivity, bulk density, hardness and microstructure analysis of Gr/Sn/PP composite. The result shows that there are significant improvement in the electrical conductivity and bulk density, which are exceeding the US-DoE target with the maximum value of 265.35 S/cm and 1.682g/cm3 respectively.

Fracture Toughness of AZ61 Magnesium Alloy with Various Thickness

The critical fracture toughness parameter KΙC of AZ61 magnesium alloy was determined on the three point bent specimens with notch designed according to ASTM E399 standard. Five specimens having different thickness, i.e., 2, 4, 6, 8 and 10 mm were considered in order to evaluate the effect on fracture toughness. The stress intensity factor range ΔK was constant ~1x 10-8 for every specimen until the critical crack length reached half of the width of the specimens. The fracture test was done with the speed rate 0.12-0.15 MPa√m/sec until the specimens broke. The experimental results showed that the critical plain strain fracture toughness KΙC is 12.6 MPa√m and the highest plain stress fracture toughness KC is 16.5 MPa√m.

Analytical Hierarchy Process for Design Selection of Micro Hot-Marking Tool

Veracious concept selection process is crucial in design engineering where, a concept with concise description will fulfill customers’ requirements. Failure in concept selection can lead to inaccurate design which will result in unnecessary process repetition of the initial stage. One of the best tools that can be used in determining the best design concept is Analytical Hierarchy Process (AHP). Micro Hot-Marking Tool (HMT) is a super-finished tool with micro tip which is to be used for alphabetical marking process using CNC milling machine. In this research, AHP was successfully employed in selecting design concept for HMT. Four significant and robust concepts were analyzed, namely C1, C2, C3 & C4. Concept 2 (C2) has been chosen as the best concept with the highest score of 27% among all the evaluated concepts which will be taken into next design stage.

The Effect of Heat Treatment on Fatigue and Mechanical Properties of 6061 Aluminium Alloy

This paper investigated the effect of heat treatment on mechanical properties and microstructure of 6061 aluminium alloy. The aluminium alloys were examined in the heat treated conditions, using different quenching media, water and oil. The alloy was solution heat treated at temperature of 529oC for one, three and five hour respectively. Aging treatment was carried out at temperature of 160oC which is assumed to be the best temperature for ageing process. Hardness measurement was carried out using a Brinell Hardness Tester Machine. The results shows hardness and impact strength are inversely proportional to each other, as the hardness of 6061 aluminium alloy decreases and impact strength increases.

V-Bend Die Forming Performance of Oil Palm Fiber Composite

Composite materials have steadily gained recognition worldwide for its uses in various sectors such as aerospace, infrastructures and automotive industries. In stamp forming of V-bend die, the most sensitive feature is elastic recovery during unloading called spring-back. This phenomenon will affect bend angle and bend curvature. This research studies the effects of tool radius, feed rate, temperature and weight ratio of fiber to Polypropylene on the spring-back of palm fiber composite. Analyzed results obtained from Design of Experiment (DOE) shows temperature, fiber composition followed by feed rate gives significant effect towards spring-back. The suggested temperature, fiber composition and feed rate to get the smallest spring-back angle in the current study are 150°C, 30wt% and 500mm/min.