S.M. Sapuan

A knowledge-based system for materials selection in mechanical engineering design

Abstract This paper studies various work on the development of computerized material selection system. The importance of knowledge-based system (KBS) in the context of concurrent engineering is explained. The study of KBS in material selection in an engineering design process is described. The development in materials databases, which sometimes serve as material selection packages, is also discussed. The use of KBS in material selection and the application in the domain of polymeric-based composite are chosen as typical examples.

Vegetable‐based biodegradable lubricating oil additives

Recently, much effort has been focused on research and development of new types of lubricating oil additives to reduce wear and friction in the tribological systems. It has been noted that the use of additives to improve the lubricating capacity and durability of oil plays an important role in the wear and friction process of materials. Due to the environmental problems, many researchers are embarking on the viability of the vegetable‐based lubricants. In this article a critical review has been made on vegetable‐based lubricant additives with specific properties and application. This article explains the advantages and manufacturing processes of vegetable‐based oils, which will give a better understanding of using biodegradable lubricating oil additives. A case study on palm oil methyl ester as an additive has been presented in this paper.

Sugar palm (Arenga pinnata): Its fibres, polymers and composites

Sugar palm (Arenga pinnata) is a multipurpose palm species from which a variety of foods and beverages, timber commodities, biofibres, biopolymers and biocomposites can be produced. Recently, it is being used as a source of renewable energy in the form of bio-ethanol via fermentation process of the sugar palm sap. Although numerous products can be produced from sugar palm, three products that are most prominent are palm sugar, fruits and fibres. This paper focuses mainly on the significance of fibres as they are highly durable, resistant to sea water and because they are available naturally in the form of woven fibre they are easy to process. Besides the recent advances in the research of sugar palm fibres and their composites, this paper also addresses the development of new biodegradable polymer derived from sugar palm starch, and presents reviews on fibre surface treatment, product development, and challenges and efforts on properties enhancement of sugar palm fibre composites.

Mechanical and Electrical Properties of Coconut Coir Fiber-Reinforced Polypropylene Composites

Abstract: Natural Fibers have an outstanding potential as reinforcement in thermoplastics. The objectives of this experiment are to evaluate the suitability of producing Fiber composites using coconut coir fibers. This study deals with the preparation of coconut coir composites by using compression technique in which good interfacial adhesion is generated by a combination of fiber modification and matrix methods. Initially the coconut fibers were treated in order to improve resin fiber interfacial bonding. The treatment agents used included alkali, stearic acid, acetone, and potassium permanganate. The various reactions between the modified fiber and polypropylene chains were used improve the interfacial adhesion between the fiber and polymer using the new bond. Generally, composites that contain treated fiber have a higher tensile modulus and greater flexural modulus than do untreated fiber composites. Typical mechanical tests on strength, flexability, hardness, and dielectric were performed and the results are reported.

Tensile Properties of Arenga pinnata Fiber-Reinforced Epoxy Composites

The aim of this study is to determine the tensile properties of Arenga pinnata fiber as a natural fiber and epoxy resin as a matrix. The Arenga pinnata fibers were mixed with epoxy resin at the various fiber weight percentages of 10%, 15%, and 20% Arenga pinnata fiber and with different fiber orientations such as long random, chopped random, and woven roving. Hand lay-up processes in this experiments were to produce specimen test with the curing time for the composite plates is in the room temperature (25–30°C). Results from the tensile tests of Arenga pinnata fiber reinforced epoxy composite are that the 10 wt.% woven roving Arenga pinnata fiber showed the highest value for maximum tensile properties. The tensile strength and Youngs modulus values for 10 wt.% of woven roving Arenga pinnata fiber composite are 51.725 MPa and 1255.825 MPa, respectively. The results above indicate that the woven roving Arenga pinnata fiber has a better bonding between its fiber and matrix compared to long random Arenga pinnata fiber and chopped random Arenga pinnata fiber. Scanning electron microscopy (SEM) tests were carried out after tensile tests to observe the interface of fiber and matrix adhesion.

A prototype knowledge-based system for the material selection of polymeric-based composites for automotive components

A prototype system for the selection of polymeric-based composite materials for automotive components is presented in this article. This prototype was developed using a knowledge-based system KEE (Knowledge Engineering Environment) tool-kit. The selection of suitable materials for automotive components, and in particular for the pedal box system, was the major emphasis of this research work. Mechanical, physical and chemical properties, together with economic and manufacturing considerations, were taken into consideration during the material selection process. These factors and others were represented as constraints and translated in the form of heuristic rules in the knowledge-based system (KBS). The KBS enabled users to select the suitable materials that satisfied all predefined criteria and constraints. A material must satisfy all these constraints in order to become a suitable candidate material for a particular component. If any one of the rules was violated, the system gave a message regarding the unsuitability of the material for a particular component.

The Effect of Environmental Treatments on Fiber Surface Properties and Tensile Strength of Sugar Palm Fiber-Reinforced Epoxy Composites

Fiber glass has been used widely in manufacturing industries, especially marine industries, because of low cost and high strength. However, glass fiber can cause acute irritation to the skin, eyes, and upper respiratory tract. This study looked at the possibility of substituting glass fiber with natural fiber in composite materials. The surface properties of sugar palm fiber (Arenga pinnata) were modified using seawater and freshwater as treatment substances. This led to biological, chemical, and water degradation of the sugar palm fiber. Morphological and structural changes in the fibers were investigated using a scanning electron microscope (SEM). A series of tensile tests based on ASTM D638-99 was carried out on epoxy composites with 15% sugar palm fiber by volume. It was found that seawater and freshwater treatments improved the surface properties of the sugar palm fiber and thus resulted in better adhesion quality as compared to untreated fiber. An improvement in tensile strength also supported this finding. Treatment with seawater for 30 days proved to be the best, with 67.26% increase in tensile strength.

A prototype knowledge-based system for material selection of ceramic matrix composites of automotive engine components

A prototype knowledge based system (KBS) for material selection of ceramic matrix composites (CMC) for engine components such as piston, connecting rod and piston ring is proposed in this paper. The main aim of this research work is to select the most suitable material for the automotive engine components. The selection criteria are based upon the pre-defined constraint value. The constraint values are mechanical, physical properties and manufacturing techniques. The constraint values are the safety values for the product design. The constraint values are selected from the product design specification. The product design specification values are selected from the past design calculation and some values are calculated by the help of past design data. The knowledge-based system consists of several modules such as knowledge acquisition module, inference module and user interface module. The domains of the knowledge-based system are defined as objects and linked together by hierarchical graph. The system is capable of selecting the most suitable materials and ranks the materials with respect to their properties. The design engineers can choose the required materials related to the materials property.

Effect of alkali treatment on mechanical and thermal properties of Kenaf fiber-reinforced thermoplastic polyurethane composite

In this study, a composite of thermoplastic polyurethane reinforced with short Kenaf fiber (Hibiscus cannabinus) was prepared via melt-blending method using Haake Polydrive R600 internal mixer. Effect of various sodium hydroxide NaOH concentrations, namely 2, 4 and 6% on tensile, flexural and impact strength was studied. Mean values were determined for each composite according to ASTM standards. Tensile, flexural and impact strength negatively correlates with higher concentrations of NaOH. Scanning electron microscope (SEM) was used to examine the surface of both treated and untreated fibers as well as fracture surface of tensile specimens. Morphology of treated and untreated fibers showed a rougher surface of treated fibers. It also showed that some of high concentrations of NaOH treated fibers have NaOH residues on their surface. This was confirmed by energy dispersive X-ray point shooting performed on the same SEM machine. Morphology of surface of fracture indicated that untreated composite had a better adhesion. Treated and untreated fibers as well as composites were characterized using Fourier transform infrared spectroscopy (FTIR). FTIR of treated fibers showed that NaOH treatment resulted in removal of hemicelluloses and lignin. FTIR also showed that untreated composite has more H-bonding than all treated composites. Thermal characteristic studies using thermogravimetry analysis and differential scanning calorimetry showed that untreated composite was more thermally stable than treated composites.

The Use of Palm Oil as Diesel Fuel Substitute

The high cost of energy supplies as well as the concern over the availability of oil have brought much pressure on many countries to search for renewable energy sources, especially after the oil crisis in 1973. Vegetable oil fuels such as palm oil fuel provide one of the alternative forms of energy that are currently being studied, particularly as a diesel fuel substitute. The purpose of this note is to review the potential of palm oil as an alternative fuel in automotive and industrial diesel engines with respect to its performance and tribological, environmental, economic and social implications.