bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Direct Active Thermal Imaging Technique for Sub Surface Delamination Detection in Aviation Composites
Authors: Aizaz Ahmad , Ali Umair
Published: October 2014

Various non-destructive testing and evaluation (NDTE) techniques are in use by the aviation industry. Thermal imaging as an NDTE tool for composite material is becoming an effective methodology. In this research, a direct energy method approach to active thermal imaging is applied with test specimen placed between the heating source and the camera to take only one diagnostics snap per unit area of region of interest (ROI). Purpose of this study is to assess the utility of direct method as a reliable NDTE technique during aerospace inspections as a quick ‘Go / No Go’ tool for the detection of sub-surface delamination in multilayered composite sheets. The research presents a quantitative comparison of temperature profiles as well as qualitative analysis of 2D active infrared thermo graphic testing of glass fiber epoxy to detect sub-surface delamination. The experimental results are in close agreement with the actual locations of delamination in test samples. The technique may serve as a reliable tool to quickly categorize the component under inspection. However, the size of delamination could not be ascertained with acceptable accuracy in this study, possibly due to the spread of epoxy to the delaminated regions during preparation of defective samples.
Topology Optimization for Robust Damage Localization Using Aggregated FRFs Statistical Criteria
Authors: Morlier Joseph , Niemann Hanno , Shahdin Amir
Published: October 2014

This work focuses on the development of a damage localization tool using Topology Optimization(TO) as a solver for the inverse problem of localization. This approach is based on thecorrelation of a local stiffness loss and the change in frequencies due to damages. We use the loss instiffness for updating undamaged numerical models towards similar models with embedded damages.This work is an extension of past work and aims at increasing the detectability of the method usingusing aggregated Frequency Response Functions (FRFs) statistical criteria. Good results have finally been achieved for the localization of close damages by the Topology Optimization method.
LCO Flutter Analysis on Coir Pressed Mat Fibre/Epoxy Composites Plate
Authors: Abdul Rahman Mohd Amirul , Mohd Rafie Azmin Shakrine , Varatharajoo Renuganth
Published: October 2014

The effects of aspect ratio and fiber-epoxy weight ratio of coir fibre/epoxy composite wing idealized as flat plate on flutter speed were preliminary studied in this current research to investigate the aeroelastic response on natural fiber composite material. The usage of natural material such as coir fiber reinforced composite might become possible solutions in future since it offers lower weight, cost reduction, and preservation of the environment factor compared to presence structures like conventional glass or carbon fiber as the reinforcement for composites. For this work, the analysis of coir fiber on aeroelastic problem will be preliminary investigated to establish related data to be served, especially in the aerospace research areas. The research began with the existing raw untreated coir fiber, which was in the form of pressed mat and originally in random oriented fiber forms, were set in the composite preparation process by simple hand-lay-up and compression moulding method under the room temperature and also controlled pressure conditions. Specimen with different aspect ratios (5, 6 and 7) with 25% wt fiber reinforcement composite was installed in the wind tunnel for subsonic experimental aeroelastic test. The result shows that the plates with lower aspect ratio have higher flutter speed.
On the Dynamic Model of a Functionally Graded Spinning Structural Element of an Aircraft Appendage
Authors: Mustapha Khameel Bayo
Published: October 2014

The use of advanced materials in automotive, aerospace and communication technologies has called for re-assessment of classical models of many structural elements. The primary objective of this study relates to the use of a higher-order continuum model for discerning the contribution of certain geometric and material properties on wave propagation behavior of a spinning appendage of an aircraft appendage. The spinning appendage is characterized by a through-thickness functional material gradation and subjected to an axial dead load. The foundation of the present model rests on the trio of the mechanics of functionally graded solid structures, the extended Hamilton’s principle and the thin beam theory. Numerical results from the wave mechanics analyses reveal the noticeable influence of axial dead load and attendant wave splitting effect caused by the gyroscopic moment of the system. The wave mechanics result paves the way for the non-destructive damage testing of the element.
Realizing Lean Concept in Automotive Parts Production: Child Parts in Sub-Assembly Line
Authors: Wan Saidin Wan Ahmad Najmuddin , Mohd Adnan Nurul Aliaa , Kasim Nazrul Idzham , Mohamed Ibrahim Azalan , Ahmad Zaidi Ahmad Mujahid
Published: October 2014

This paper addresses the application of a promising and concept known as Lean Manufacturing (LM) concepts that can be used to prevent incorrect parts size at subassembly 1 and 5. In the context of size versus volume, the possibility of small parts to encounter defects is much greater compare to huge size. This undesirable circumstance will lead to the financial deficits in terms of waste. At this stage, this paper will identify and investigate the sources of inputs that cause the failure in the manufacturing system. The finding of the failure will be analysed and extending to the problem solution by suggesting the lean approach at the allocated area. By adapting some of this approach, it will deliver to the performance of production line that includes an assessment of fulfilling the objectives in terms of preventing parts incorrect size, reducing related cost from waste and providing customer with quality products. Taking into account of the objectives, the implementation of this approach in the sub assembly line is then described. Nevertheless, further investigations are necessary to improve the proposed applications which currently function with limitation due to small area of production line.
Life Cycle Costing Model for Hollow Fibre Membrane Module: A Review and Further Research
Authors: Jiran Nur Syamimi , Saman Muhamad Zameri Mat , Mohd Yusof Noordin , Zakuan Norhayati
Published: October 2014

Increasing human population increases the demand for fresh water supply. Membrane technology has been identified as one of the solutions to reduce water pollution due to industrial activities, especially the chemical industry. In order to promote this technology and shift from the traditional system, economic aspect is an important attraction. The total cost for owning, operating, using and post-using the technology will influence the industry to invest this technology in their workplace. Therefore, a life cycle costing (LCC) analysis should be performed to estimate the complete overall cost of the membrane system from cradle-to-grave. This paper aimed to review some economic analysis of the membrane system, previous LCC model and highlight the initial step in performing LCC analysis of hollow fibre membrane module, which is to identify all primary and secondary activities and all possible costs related to the module.
Employees’ Perception on Lean Production System Implementation: A Case of Malaysia Automotive Component Manufacturer
Authors: Che Mamat Rusalbiah , Md Deros Baba , Rahman Mohd Nizam Ab. , Ahmad Jamil Norina
Published: October 2014

Stiff competitions, fluctuation in demand and changes in customer preferences have prompted the automotive component manufacturers worldwide to enhance their manufacturing system. Lean Production System (LPS) is a proven method used by many automotive component manufacturers to maintain their competitiveness. Although research on lean implementation has been conducted extensively, there is still a limited number of studies on the LPS implementation from the employees’ point of view. Thus, the main purpose of this study is to investigate the LPS implementation from the employees’ perspectives in an automotive component manufacturer in Malaysia. Both quantitative and qualitative methods were employed in this study. A survey questionnaire was developed from previous literature and distributed to 50 middle and lower level employees. The questionnaire was pilot-tested by the employees and also verified by the industry experts. Structured interviews with 25 employees were conducted to determine their perceptions and problems encountered during the LPS implementation. The result of the study revealed that majority of the employees in this company were only aware of 5S and Kaizen although there are many other LPS tools which are also useful to them. However, the employees agreed that the LPS give many benefits in the workplace. Another finding was Employee Involvement (EI) in the LPS was mostly in the form of sharing responsibility with their co-workers. Problems were due to the lack of knowledge and training in the LPS among the employees. Greater effort should be taken by the company to ensure successful LPS implementation and its sustainability over time.
Design Evaluation Method for Design Engineer in Manufacturing Industries Using Integrated Rough-Grey Analysis Approach
Authors: Turan Faiz , Omar Badrul
Published: October 2014

In order to remain competitive in today’s technologically driven world, the faster and more efficient development of innovative products has become the focus for manufacturing companies. In tandem with this, design evaluation plays a critical role in the early phases of product development, because it has significant impact on the downstream development processes as well as on the success of the product being developed. Owing to the pressure of primary factors, such as customer expectations, technical specifications and cost and time constraints, designers have to adopt various techniques for evaluating design alternatives in order to make the right decisions as early as possible. In this work, a new methodology for design evaluation has been developed. The preliminary stage quantifies all the criteria from different viewpoints through the process of scale of “Weighting criteria”. The next stage uses a modified Rough-Grey Analysis to obtain the alternatives weighting or ranking of the alternatives. This method will enable designers to make better-informed decisions before finalising their choice. Case example from industry is presented to demonstrate the efficacy of the proposed methodology. The result of the example shows that this new method provides an alternative to existing methods of design evaluation.
Experimental Design for Reverse Assembly Based Disassembly Process
Authors: Abdullah Nurhidayu , Azni Jafar Fairul , Maslan Mohd Nazmin
Published: October 2014

Product disassembly is a vital strategy for industrial recycling and remanufacturing which generates the desired parts and/or subassemblies by means of separation of a product into its elements. In order to increase disassembly capacity while maintaining the parts quality, new standards had to be established. Manual disassembly work perform by human will create inconsistency in the quality, efficiency, as well as time consuming, whereby it is believe that those weaknesses can be overcome by an automated performance. Therefore, this research work will re-evaluate the existing approach of disassembly process; reverse-assembly method in disassemble a mini toy car. The design methodology is conducted to verify the disassembly process performance and identify factors affecting the performance. The disassembly process experiment will be conducted in two ways; manual and semi-automated disassembly. This paper reviews the design process of the proposed experimental methodology. The important components of the experimental methodology are discussed in this paper.
Energy Saving Measures for University Public Library: A Case Study of UTHM Library
Authors: Noranai Zamri , Mohamad Mohd Hafiz Haidar , bin Salleh Hamidon , Yusof Mohammad Zainal M.
Published: October 2014

Energy is an important source of power for human daily activity. Energy efficiency is measured by the productivity of the system which goes through under certain condition as to achieve results at optimum level. The basic purpose of this study is to reduce and save energy consumption in order to determine the energy efficiency of public university library. Thereby saving measures can be identified from the building services installed in the library. From the findings, there are two major system correlates which is mechanical and electrical system. Based on these systems, it could resolve intricacy issues regards to building efficiency by conducting an Energy Saving Measures (ESM) in context of Malaysia’s tropical setting. Lack of supervision and excessive wastage of energy will render inefficient in both systems which would decrease the optimum level of performance and reliability issues. The study emphasizes that energy conservation should be prioritized in order to avoid unregulated energy consumption. Hence, it could focus on the main streamline where energy efficiency is a possible and potential sustainable building in the present and future for better surroundings and standard quality of life.
Welding Parameter Optimization of Surface Quality by Taguchi Method
Authors: Ng Chuan Huat , Hamjah Mohd Khairulamzari
Published: October 2014

An experimental study of GTAW was conducted to determine the optimization of weld parameters on the droplet formation in the surface quality of weld pools. These optimization investigations consisted of welding current, welding speed and feed rate. The strength and surface quality of weld pool were measured for each specimen after the welding parameter optimizations and the effect of these parameters on droplet formation were researched. To consider these quality characteristics together in the selection of welding parameters, the Orthogonal Array of Taguchi method is adopted to analyze the effect of each welding parameter on the weld pool quality, and then to determine the welding parameters with the optimal weld pool quality.
An Experimental Investigation into Different Distortion Control Techniques in Welded T-Joints
Authors: Mir Sadat Ali , Ch. Srinivasa Rao
Published: October 2014

Welding is a reliable and effective metal fabrication process which is widely used in industries. Localized heating during welding, followed by rapid cooling generates residual stress and distortion in the weld and base metal. In the last few decades various research efforts have been directed towards the control of welding process parameters aiming at reducing the residual stress and distortion. In the present paper the distortion in fillet welds and the affect of the distortion control techniques on the welded joint are studied. The welding is done with different process parameetrs and under different surrounding conditions. Due to this the distortion level in the T Joint was measured and observed. The study is necessarily aimed at developing the prediction and controlling techniques for distortion in welded T-joints. Key Words: Distortion, preheating, peening, leg length, Shielded metal arc welding (SMAW), Manual metal-arc welding (MMAW)
Effect of Nitrogen Gas and Nitrogen-Oil-Mist Conditions when Turning of STAVAX ESR Steel
Authors: Elshwain Amad Elddein Issa , Redzuan Norizah , Noordin Mohd Yusof
Published: October 2014

Conventional coolant/lubricants have some drawbacks such as high cost, pollution, and unsatisfactory product quality. New cooling approach by using gases to enhance machinability has been investigated. This study presents the finding of nitrogen gas and nitrogen-oil-mist as conditions when turning of hardened stainless tool steel (STAVAX ESR) with hardness 48 HRC. Turning experiments were carried out on CNC turning machine using rhomboid type wiper coated carbide cutting inserts. The result show that better product surface finish and longer tool life, as well as decrease cutting temperatures could be achieved by using nitrogen-oil-mist condition compared to nitrogen gas condition.
Influence of the Supplementary Cementitious Materials on the Dynamic Properties of Concrete
Authors: Elbahi Elbachir , Boukli Hacene Sidi Mohammed El Amine
Published: October 2014

The resonance frequency method is one of many non-destructive tests which allow us to evaluate construction materials. It was used to determine the dynamic properties of concrete, required in structures design and control, also considered as the key elements for materials dynamic. In this study, we chose a non-destructive approach to quantify-in laboratory-, the influence of adding “crushed limestone” and “natural pozzolan” on local concrete’s dynamic characteristics. However, several concrete mixtures have been prepared with limestone aggregates. The experimental used plan, allowed us to determine the dynamic modulus of elasticity, the dynamic modulus of rigidity of different formulated concretes.
Electrical Characterisation of Highly Doped Triangular Silicon Nanowires
Authors: Za’bah Nor F. , Kwa Kelvin S.K. , O'Neill Anthony
Published: October 2014

A top-down silicon nanowire fabrication using a combination of optical lithography and orientation dependent etching (ODE) has been developed using <100> Silicon-on Insulator (SOI) as the starting substrate. Initially, the samples were doped with phosphorus using the diffusion process resulting in carrier concentration of 2 x 1018 cm-3. After the silicon nanowires were fabricated, they were measured using a dual configuration method which is similar to the four-point probe measurement technique to deduce its resistivity. The data obtained had suggested that doping distribution in the silicon nanowires were lower and this may have been affected by the surface depletion effect. In addition, with respect to carrier mobility, the effective mobility of electrons extracted using the four-point probe data had demonstrated that the mobility of carriers in the silicon nanowire is comparable with the bulk mobility. This is most probably due to the fact that in this research, the quantum confinement effect on these nanowires is not significant.
Effect of Nitriding on Reaction Layer of Diffusion Bonded Sialon to AISI 420 Martensitic Stainless Steel
Authors: Md Ibrahim Nor Nurulhuda , Hussain Patthi , Awang Mokhtar
Published: October 2014

Joining sialon to as-received and nitrided AISI 420 martensitic stainless steels using diffusion bonding is reported in this paper. The samples were joined at 1200°C for one hour under uniaxial pressure of 17 MPa in a vacuum (1x10-5 Torr). After joining process, the microstructure, interdiffusion of elements, and hardness of the joint were studied. The interdiffusion and reactivity of the elements created the reaction layer. It consisted of interface layer on the sialon side whereas thicker diffusion layer was formed on the steel side. Thinner reaction layers were observed in joining sialon to nitrided steels compared to joining sialon to as-received steel due to less reactivity between the joined materials. However, more precipitates such as carbides were formed in the parent steel with longer nitriding time. Gaps were formed between the diffusion layer and the parent steel but the interfacial bonds were strong since no cracking occurred on the samples. Since the reaction layer had intermediate hardness, it contributed to the joint’s ductility that reduced the effect of thermal expansion mismatch between the joined materials by acting as a shock absorbing zone.
Microstructure and Adhesion of NiAl/Al and NiAl/Ni Coatings Formed by SHS Process
Authors: Riyadi Tri Widodo Besar , Zhang Tao , Sarjito Sarjito
Published: October 2014

The objective of thiswork was to investigate the microstructure and adhesion of NiAl coating whichformed by self propagation high temperature synthesis (SHS) process. Ni/Almixture and an underlayer material which used Ni and Al were compacted to forma bilayer pellet and subsequently put on a steel substrate. The Ni/Al reactionwas ignited using induction heating in a combustion chamber of argon gas. Themorphology and microstructure of the products were observed using SEM and XRD.The results showed that further reactions between NiAl coating and underlayermaterials formed several intermetallic phases. The role of Al and Ni underlayeron the microstructure, porosity and the adhesion between coating and thesubstrate was observed.
Effect of High Cerium and Lanthanum on Impact Toughness of Al-11Si-Cu Eutectic Cast Alloy
Authors: Ahmad Rosli , Asmael M.B.A. , Ourdjini Ali
Published: October 2014

The effect of additive elements on impact toughness of Al-11Si-Cu alloy was investigated. The impact test bars were used as impact specimens. The energy of Al-11Si-Cu was improved with Sr modifier addition. The high ability of Ce and La to form large structure intermetallic in Al-Si-Cu will reduce the energy. The RE-intermetallic has an effect on impact analysis, which facilitates to increase the porosity pore.
Effect of Cathodic Hydrogen Charging on Mechanical Properties of AISI 304 Austenitic Stainless Steel Welds
Authors: Deraman Rasdi , Berhan M.N.
Published: October 2014

A welding coupon of AISI 304 austenitic stainless steel with thickness of 5 mm was welded by Gas Metal Arc Welding (GMAW) process using different welding parameters. The rectangular tensile test specimens (ASTM E8 standard) were subjected to cathodic hydrogen charging by immersed in 0.3 M sulfuric acid (H2SO4) solution and charged with current density rate of 110 mA per cm2 for 12 hours. The effect of cathodic hydrogen charging on the microstructural properties and fracture behavior in welding joints have been examined using an optical microscopy and scanning electron microscopy (SEM). The results showed that the percentage decay of UTS and elongation in welding coupons were reduced because of hydrogen charged. The fractured surfaces in weld joints zone appeared a formation of globular oxides.
Effect of Ti Addition on Oxidation Behavior and Area Specific Resistance of Fe-20Cr Alloys for SOFC Interconnects
Authors: Ruhma Zaka , Setiawan Asep Ridwan , Ramelan Aditianto , Suratman Rochim
Published: October 2014

In this work, the oxidation behavior of Fe-20wt.%Cr alloys with different titanium contents: 0, 0.5, and 1 wt.% are studied as a function of time in air atmosphere. The samples were isothermally oxidized at 700°C for 24, 48, and 96 h in a box furnace. The area specific resistance of oxides formed at the alloys surface during oxidation is measured by four-point probe methods at 700°C for 24 h. For Ti containing alloys, surface morphology observation by SEM shows that a few of TiO2 particles formed on the top of Cr2O3 scales. Continous TiO2 layer was not formed at the alloys surface after oxidation. XRD analysis on the oxide scales of Fe-20Cr-Ti alloys confirms that Cr2O3 and TiO2 oxide formed on the alloys. Ti addition into the alloys increases the oxidation rates of alloys at the initial stages. Oxidation behavior of Fe-20Cr-0.5Ti and Fe-20Cr-1Ti alloys showed two regimes. The parabolic rate constant, kp (in gr2/cm4s) were 1.57 x 10-13 and 3.08 x 10-13 respectively for initial stage of oxidation then changed to-9 x 10-15 and-3 x 10-14 respectively for the remainder of the test. ASR measurement shows that the presence of Ti in the alloys decreases the electrical resistance up to 60%. Ti addition into Fe-Cr alloys affect the oxide growth rate and increase the conductivity of Cr2O3 scales.
The Effect of TiCl4 and Chitosan Concentration on the Coating of TiO2 on Iron Foam Substrate by Self-Assembled Monolayer Method
Authors: Ramdan Raden Dadan , Sunendar Bambang , Benindra Axel Emmanuel , Hermawan Hendra
Published: October 2014

Iron foam is a type of material having potential to be used as water or air filter andimplant material. One of the limitations of this material is its high reactivity on corrosion. In thepresent research TiO2 coating on iron foam substrate has been developed by self-assembledmonolayer method. Focus is given on the effect of TiCl4 and chitosan concentration on thecharacteristic of the developed TiO2 layer. Precursor was prepared with HCl concentration of 0.5; 1;1.5 M and chitosan solution concentration of 1% ; 2% ; 4% (w/v). Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy (EDS) characterizations show that TiO2 particles areformed on the iron foam surfaces. It was observed that with the higher TiCl4 concentration moreTiO2 particles obtained on substrate surfaces. On the other hand, SEM results also show the averageTiO2 particles size at around 1 micrometer and in tetragonal shape. It was observed that with thehigher chitosan concentration, the particles shape tend to have tetragonal stucture, while at lowerchitosan concentration (1%), agglomeration of TiO2 particles were observed.
Effect of Die Gap and Punch Travel on Springback in Air V-Bending Process Using Taguchi Method
Authors: Buang Muhamad Sani , Abdullah Shahrul Azam , Saedon Juri
Published: October 2014

Springback is a serious problem for the manufacturing industry due to error in the appearance of the final product especially in bending process. Therefore, it's important to investigate the factors that affect the springback behavior . This paper focused on the effect of two parameters, namely die gap and punch travel on springback behavior in air V-die bending process for stainless steel sheet metal. Different values of die gap and punch travel were experimentally used and the final bent angle was measured. Design of Experiments (DoE) was based on Taguchi Method (TM) and the optimum parameters was obtained using signal-to-noise (S/N) ratio. Further analyzed, Analysis of Variance (ANOVA) techniques was carried out to investigate which of the factors are significance on springback effect. The result show that punch travel is the most significance factor than die gap factor based on p-value for punch travel and die gap were 0.003 and 0.045, respectively. From this two factors, punch travel is most considered to reduce springback phenomenon compared to die gap and the effect could be improved through modification of this parameter.
Effects of Temperature and Strain Rate on Commercial Aluminum Alloy AA5083
Authors: Mohd Nor Mohd Khir , Mohamad Suhaimi Ibrahim
Published: October 2014

Superplastic forming, SPF is a special metalworking process that allows sheets of metal alloys such as aluminum to be stretched to lengths over ten times. Nowdays, only a few aluminium alloys can meet the specific requirement of SPF manufacturing process and not much data available to represent their mechanical behaviour. In order to deal with this issue, this research project is conducted to investigate the characteristics of commercial aluminum alloy, AA5083 when tested at different strain rates and temperatures. These parameters play a crucial roles in the design and manufacturing processes of military, automotive and aerospace structures. Equally, the effects must be considered in the constitutive model development to accurately capture the deformation behaviour of such materials. The specimens were prepared according to 12.5mm gauge length standard. The Uniaxial Tensile Tests were carried out at various strain rate from 4.167 x10-1 s-1 to 4.167 x10-5 s-1 over a wide temperature range from ambient to 95°C. The experimental data shows that increasing strain rate increases flow stress, while increasing temperature decrease flow stress. This is leads to important conclusion that material AA5083 exhibits strain rate and temperature sensitivite, and suit with the SPF operating condition.
Soda Anthraquinone Pulping of Oil Palm Male Flower Spikes
Authors: Masrol S.R. , Ibrahim Mohd Halim Irwan , Adnan Sharmiza , Amir Shah Muhammad Safiuddin Syah , Main N.M. , Faizal Esa , Othman Mohd Hilmi
Published: October 2014

This study was carried out to investigate the characteristics of pulp and paper produced from oil palm oil male flower spikes (OPMFS). The evaluation of the pulping process was studied based on the chemical Soda Anthraquinone pulping process. 60 gsm papersheet of oil palm male flower spikes were prepared from unbeaten and unbleached OPMFS Soda-AQ pulp. All optical, physical and mechanical characteristics were investigated according to TAPPI and MS ISO standards. OPMFS pulp recorded value of 6.42 s, 353 ml, 76.5 %, 36.7 % and 9.35 for drainage time, freeness, moisture content, screened yield percentage and Kappa number respectively. OPMFS paper sheet recorded value of 56.99 g/m2, 131.11 µm and 0.43 g/m3 for grammage, bulking thickness and apparent bulk density respectively. Unbleached OPMFS paper also recorded 26.49 % and 43.50 % for brightness and opacity. For mechanical characteristics, OPMFS paper recorded 39.10 N.m/g, 8.32 mN.m2/g, 3.15 kPa.m2/g and 38.50 for tensile index, tear index, burst index and folding endurance (no.) respectively. This research demonstrate some potential characteristics of oil palm male flower spikes (OPMFS) paper to be investigated as a newly explored non-wood based raw material for papermaking.
Optimum Excess Air for the Utilization of Palm Biodiesel Blends in Fire Tube Boiler
Authors: Rachman Susila Arita , Komariah Leily Nurul
Published: October 2014

Biodiesel has great potential to be applied in a variety of combustion engines, such as boiler. The excess air control in the combustion process plays an important role to produce an ideal combustion performance. The changes in the physical properties of the fuel due to the use of palm biodiesel or its blends affect the amount of required air to the combustion chamber. This study was conducted in a package type fire tube boiler with a design pressure of 3 bars and heat capacity of 60,000 kCal/hour. Palm biodiesel blends were set as boiler fuel with composition of 10%, 20%, 30% and 50% in diesel oil. Fan damper scale is part of the burner system that in charge to regulate the air flow into the combustion chamber. The fan damper scale was set in the range of 4.0-4.9. For higher blends of biodiesel, the fan damper was optimum in lower scale (4.0 or less). More biodiesel in blends, less combustion air was needed to enter. Hence, the excess air of palm biodiesel combustion in fire tube boiler was in range of 57-66%.
Effect of Injector Nozzle Design on Spray Characteristics for Hydrogen Direct Injection Engine Conditions
Authors: Mansor Mohd Radzi Abu , Samiran Nor Afzanizam , Mahmood Wan Mohd Faizal Wan , Raja Nazatul Akhma
Published: October 2014

Hydrogen has a unique flammability property compared to other fuels. Previous researches proved that direct injection is the most suitable method for this particular fuel. This research aims to study the effect of injector nozzle geometry on mixture and internal combustion efficiency in four stroke automotive engine which operates using hydrogen fuel. The research will concentrate on two aspects, namely the inflow and outflow profile of the injector nozzle. For each flow profile, the effect of geometrical design of the nozzle on the parameter such as flow velocity, fuel penetration distance, average mass fuel consumption and diffusion will be studied in detail. In this study, numerical simulation analysis was done by using the computing fluid dynamics (CFD) software, Star-CCM+. Models comprise of multiple orifice nozzle geometry with single angle orifice and double angle orifice was developed with CAD software. A suitable design for a better mixing nozzle would then be determined. Nozzle which possesses a high number of orifice and a smaller diameter will result in a higher flow velocity in the cavity nozzle channel. Geometry of nozzle with different angle of orifice was found to be the most suitable due to the low flow penetration distance and fuel consumption as well as combustion enhancement by the diffusion rate.
Effect of Mixture Formation of Biodiesel-Water-Air Rapid Mixing Derived from Crude Palm Oil and Waste Cooking Oil in Burner Combustion
Authors: Suardi Mirnah , Azman Norazwan , Samsudin Dahrum , Amirnordin Shahrin Hisham , Khalid Amir
Published: October 2014

The trade-off between NOx and PM is a main issue in the observation of combustion characteristics, NOx and PM are released from the combustion of biodiesel either in internal combustion engine or external burner system. Thus, the rapid mixing of biodiesel-water-air technique is one of the most significant approaches to the reduction of pollutant emissions of burner combustion. In this research, the relation between the mixture formation of biodiesel spray and burning process was investigated in detail in order to understand the effects of the changes of fuel properties in fuel evaporation. In these experiments, different types of biodiesel fuel derived from the crude palm oil and waste cooking oil were used in the same nozzle characteristics of burner system. This study focuses on the observation of the real images of the spray characteristics together with equivalent ratio, water content, spray penetration length, spray angle and spray area. Water emulsion of percentage up to 15vol% and blending of biodiesel ratio was varied from 5vol%-15vol%. The diesel fuel have been compare with based analyzed of real spray images with the times change. The results shows percentage of biodiesel and shows the higher of water content due to the higher viscosity affects the higher penetration length and lower spray angle and influence the flame penetration.
Influences of Cylinder Wall Temperature on Heat Release during Compression Period
Authors: Ramsy Him , Ahmad Thahir , Jaat M. , Khalid Amir
Published: October 2014

Compression period in a diesel engine is generally seen as initial characteristics before injection into combustion chamber. A free-piston type rapid compression machine (RCM) has been designed simulate the combustion phenomena in order to observe the chemical and physical kinetics studies at elevated pressures and temperatures. Purpose of this study is to clarify the effects of wall cylinder temperature on air heat release, especially during compression period. This method can a light piston is pneumatically shot and gets hammered in stopper at compression end. Measurements were made on a light piston compress in a rapid compression machine (RCM) with intended to simulate the actual compression period related phenomena. During this phenomena, the ambient temperature influences from the cylinder wall temperature has appear beneficial for the biodiesel fuel premixing and achieving best mixture preparation There are three tests will used to investigate the effects of the variant temperature of wall cylinder during compression period. Results show high temperature on cylinder wall will be effects decrease during temperature drop after compression stroke. The new characteristics rapid compression machine (RCM) is to develop and analyse before combustion process.
Experimental Investigation of Mixture Formation and Flame Development Using the Basics Technique of Schlieren Optical Visualization Principle
Authors: Samsudin Dahrum , Othman Safwan , Anuar M.D. , Manshoor Bukhari , Khalid Amir
Published: October 2014

The Schlieren technique remains to be one of the most powerful technique to visualize the flow and it is relatively easy to implement, high and variable sensitivity, low cost and its used conventional of light. This technique allows us to see the invisible of the optical inhomogeneities in transparent media like air, water and glass that otherwise cause only ghostly distortions of our normal vision. This research investigates the mixture formation and flame development of biodiesel fuel using the Schlieren optical visualization principle. This method can capture spray evaporation, spray interference, mixture formation and flame pattern clearly with real images. During the experiment, the camera lens was used with telephoto lenses (Nikon 70-300mm f/4-5.6G) in order to capture a large amount of light especially the low flame intensity during the initial flame development. The flame development was captured with color images from a color digital video camera. This method can capture the flow of fluids of varying density, such as spray evaporation, spray interference and mixture formation clearly with real images. The result shows that the mechanism of fuel-air mixing and a better comprehension of combustible mixture that can give valuable information to improve and optimize the combustion process.
Study on the Rudder Effect to the Lateral and Directional Flight Behaviors of the Turbojet Driven Light Aircraft
Authors: Al Aian Ahmad Eshtiwey , Basuno Bambang , bin Omar Zamri
Published: October 2014

The present work focuses on the development of computer code related to the lateral stability analysis on a jet engine aircraft model. The computer code designed in such a way, so for a given aircraft data will produce the result in term of: 1) Lateral directional dimensional stability derivatives, 2) Lateral directional responses following rudder maneuver with respect to the time, 3) The lateral direction transfer function for the rudder maneuvers, 4) The relationship between rudder deflection and lateral angle of attack (sideslip angle) β, the Euler roll angle ɸ, and Euler yaw angle ψ with respect to the time maneuvers. Through this developed computer code can make an assessment the lateral behavior for the turbojet driven light aircraft [1].
Adjustable Acoustical Performance Based on Deformable Origamic Shapes: A Preliminary Experimental Investigation
Authors: Muarat Nurul Farhanah , Hussein Mohamed , Hamzah Raja Ishak Raja , Ahmad Z.A.B. , Mohamad Maziah , Zain Mohd Zarhamdy Md , Isa Norasikin Mat
Published: October 2014

This paper describes a preliminary investigation on the possible use of deformable origamic shapes as a technique to provide adjustable acoustical performance in multi-purpose hall. The term ‘deformable’ means that the origamic shape undergoes deformation which automatically resulted into the change of its geometrical configurations. The experimental investigation has been carried out on three types of origamic shapes with several geometrical configurations. The measurement tests were conducted in a reverberation room and in accordance to ISO 354:2003 Measurement of Sound Absorption Coefficients in a Reverberation Room. Findings from the preliminary investigation show good trends indicating that the origamic shapes have the capability of adjusting the sound absorption coefficients by varying their geometrical configurations. Following those results, future works with details investigation will be undertaken as to validate the preliminary results.
Computer Simulation of Fracture Process in Compressive Failure of Cross-Ply Laminate of Composite Materials
Authors: Nadabe Takeaki , Takeda Nobuo
Published: October 2014

This study investigates the computer simulation of fracture process in compressive failure of cross-ply laminate of composite materials. The purpose of this study is to establish the numerical analysis method to understand the fracture mechanism and predict the mechanical response of composite materials through the computer simulation. The stacking sequence of the simulated laminate is [0/90] s. The reinforcement fibers in 0-degree plies are modeled by circle cross-section beam elements to represent the three-dimensional effect in bending of fibers. Cohesive elements are inserted in the connection of beam elements to simulate the bending breaking of fibers. For the purpose of parallel computing, the domain decomposition method is applied, and for pre-conditioned conjugate gradient algorithm, incomplete Cholesky conjugate gradient method is applied. The simulated results show that in the initial state of the loading, the stress concentration occurs around the initial misalignment of fiber in 0-degree plies, and it also occurs around the area where fibers come close in 90-degree plies. At average applied strain 1.20 %, the fiber breaking damage initiates in 0-degree ply, and after this point the damage develops in the material. The simulated damage is close to the microscope picture of the actual composite materials obtained in the experiment. The current simulation is considered to correspond with the actual material deformation.
Prediction of Energy Absorption of Al-Based FGM Crash Box under Quasi-Static and Dynamic Loading
Authors: Zainal Abidin Mohamad Rusydi , Jamian Saifulnizan , Muhd Nor Nik Hisyamudin
Published: October 2014

In this study, simulations of quasi-static and dynamic loading on the Al functionally graded materials (Al FGM) crash boxes are carried out. The FGM crash box is fabricated by heat treatment method. Five different crash boxes, namely FGM0, FGM1, FGM2, FGM3 and FGM4 for the different heat treatment temperatures of 25, 500, 520, 540 and 560 °C, respectively are investigated. The simulation results of quasi-static loading test show that FGM1 has the maximum force of 97.515 kN and the highest specific energy absorption (SEA), 33.029 kJ/kg. As for dynamic loading test, FGM3 has recorded the highest maximum force, 59.379 kN and FGM2 has recorded the highest SEA, 24.17 kJ/kg. It can be concluded that the strength and SEA of crash box is increased by introducing FGM concept.
Stress Analysis of the Impactor Assembly of the Dropped Weight Impact Testing Machine
Authors: Van Trong Nguyen , Gunawan Leonardo , Jusuf Annisa , Dirgantara Tatacipta , Putra Ichsan Setya
Published: October 2014

This paper presents the stress analysis of an impactor assembly of a dropped weight impact testing machine. A finite element analysis was performed to calculate the stress occurred on the impactor during the impact which should be less than its yield strength. By varying the level of the reaction load from the specimen to the impactor, the maximum load that can be withstand by the impactor assembly without plastic deformation was predicted. Then, several simulations were carried out to find the best way to increase the load limit of the impactor. It was found out that increasing the thickness of box to 7 mm and both the diameter of arm and frame-column to 40 mm will increase the load limit by 236%.
Impacted of Vacuum Bag Woven Kenaf/Fiberglass Hybrid Composite
Authors: Yunus Syarifah , Salleh Z. , Aznan M.A. , Berhan M.N. , Kalam A. , Rashid A.A. , Wong Freddawati Rashiddy
Published: October 2014

This paper discusses the mechanical properties of woven kenaf/fiberglass hybrid composites which has been fabricating using vacuum bag technique. Kenaf fiber had chosen among others natural fibres due to its excellent mechanical properties and potential natural raw fiber to replace plastic or tobacco in manufacturing a multitude of products for the construction, automotive, textile and advanced technology sectors. This study investigates post impact tensile of kenaf hybrid composites and its surface fractured. The impact energy used consists of 4J, 6J, 8J, 12J and 16J. The specimens were clamped between two plate rings with an internal hole diameter of 18mm and impacted with hemispherical nose impactor shape with diameter size of 12.7mm. The results revealed that this kenaf hybrid composite showed significant decreasing of strength and modulus as increasing the impact energy. The damage area affected with fiber fracture occurred much later in fracture process due to high bending stresses.
Investigation on the Tensile Strength of Treated and Untreated Woven Sugar Palm Fibre Reinforced Composites
Authors: Mahzan Shahruddin , Bahtiar Wahieda M. , Mohamad Zaleha
Published: October 2014

Natural fibres offer environmental benefits such as biodegradable and can be obtained from renewable resources. However, there is lack of investigations done to characterize and compare different types and orientation done on the natural fibres. This paper determines the tensile strength of sugar palm fibres under various treatment processes. The composites were fabricated using woven sugar-palm fibre treated with alkali and acid and used epoxy resin as the matrices for the composite. The tensile test was done to determine the tensile strength of the composite and the surface morphological analysis was done using SEM. The results demonstrated that the composite with the alkali treated fibres produced higher tensile strength compared to untreated and acid treated fibres. With these properties, it shows that treated woven sugar-palm fibre composite can withstand high stress load during operation compared to untreated fibres reinforced composites.
Characteristics of Adhesive Joints under Rate-Dependent Tensile Loading
Authors: Johar Mahzan , Wong King Jye , Tamin Mohd Nasir
Published: October 2014

Effects of loading rates on deformation and mechanical properties of adhesive joints are examined in this study. For this purpose, acrylic foam pressure sensitive adhesive (PSA) was employed with aluminum adherents. Tensile loading of the adhesive joint was applied at displacement rates ranging from 5 to 500 mm/min. Results show that the tensile load-displacement response is characterized by three regimes, namely an initial non-linear behavior with initiation of cavities, a hardening behavior through fibrillation process and the final fracture of the stretched fibrils. The strengths of the adhesive joints increases asymptotically from 0.56 to 1.92 MPa over the displacement rates from 5 to 500 mm/min. Both modulus and strain energy density at fracture reach optimum level around a displacement rate of 100 mm/min. Adhesive failure of the joint dominates at low loading rate (below 10 mm/min.) while cohesive failure is prominent at faster loading rates above 250 mm/min.
Finite Element Simulation of Ductile Failure Process of Spot Welded Joint under Tensile Loading
Authors: Kosnan Mohamad Shahrul Effendy , Ahmad Zaini , Borhana Abdoulhdi Amhmad , Tamin Mohd Nasir
Published: October 2014

Deformation response and failure process of a spot welded joint are investigated in this study. For this purpose, a cross-tension spot welded joint sample made of dual phase steel sheets (DP600) is prepared and tensile tested to failure. Complementary FE simulation of the test is performed. The FE model acknowledges the variation of properties across the spot welded region. Rice-Tracey ductile damage model is approximated and employed in the simulation. Close comparison of load-displacement curves and deformed shape with measured values serve as validation of the FE model. Results show that FE simulation with damage-based model adequately predicts tensile deformation and failure of the spot welded joint. Tensile failure of the joint is confined to the heat affected zone and heat affected/fusion zone interface of the joint. Localized through-thickness necking of the sheet metal is captured. In addition, the predicted fracture of the spot welded joint is accompanied by localized extensive plastic deformation.