Faculty of Engineering and Built Environment
Universiti Kebangsaan Malaysia

Volume 20 (2008)

Table of Contents

No. Article


1. A Case Study on The Implementation of Quality Control Circle In The Production Line of A Manufacturing Company
Norhamizah Satar & Baba Md DerosAbstract
This paper is based on a case study of Quality Control Circle (QCC) implementation in the production line of a manufacturing com pan ,: n Malaysia. In this paper, the authors would like to share their experience of a success story in implementing the QCC, which is known as Small Group Activity (SGA) in their production line.The SGA was implemented with total involvement of its employees and fully supported by committed top management. As an example, the authors discuss their experiences in detail the SGA activities implemented in the production-engineering department. The case study presented showed and proved that by empowering the lower level employees through implementing QCC activity, the company had gained a substantial human development and cost savings. Finally, the authors also like to share the problems that they had encountered during the implementation of the SGA activities and how they had remedied these difficulties.

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2. Characterization of Metal Injection Molding (MIM) Feedstock Based on Water Soluble Binder System
Muhamad Hussain Ismail, Norhamidi Muhamad & Mohd Afian OmarAbstract
Metal Injection Molding (MI M) is a new manufacturing technique especially to produce small and complex precision parts. Charaterization of feedstock is one of the important tasks in order to evaluate the homogeneity level of the feedstock prepared and to control the quality of the parts during injection molding process. This paper attempts to investigate the characteristics of the MIM feedstock by performing rheological test using the feedstock consisted of 316 L stainless steel powder with a mean particle size of 12 um and a major fraction of water soluble binder system known as polyethylene glycol (PEG). Three different weight percentage of PEG at 65, 75 and 85 respectively were used during the investigation. The viscosity of MIM feedstock at different temperatures and shear rates were measured and evaluated. Results show that increasing the PEG content would decrease the viscosity of the feedstock. The rheological properties of the feedstock showed that the proposed method of mixing is adequate to produce a homogeneous feedstock that is favorable for injection molding process.
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3. Validating A Conceptual Framework For Benchmarking Implementation in SMEs At Six Case Studies
Baba Md Deros, Sha’ri Mohd Yusof & Azhari Md SallehAbstract
This paper presents the case study results of a conceptual framework for benchmarking implementation in Small and Medium Enterprises (SMEs), which had taken into consideration of SMEs strengths, weaknesses and characteristics. This framework provides a guide on the approach “how to” implement benchmarking, which is simple in structure, systematic and easily understood.The conceptual framework described in this paper was based on gradual implementation and selection of the appropriate key performance measures and benchmarking techniques as and when necessary, with the ultimate aim of improving business competitiveness and performance. Finally, the paper culminates with discussions, suggestions and comments by six case study companies with respect to the conceptual framework applicability and usability in the SMEs environment.
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4. Use of Strain-Life Models With Wavelet Bump Extraction (WBE) for Predicting Fatigue Damage
Shahrum Abdullah, Choi Jae-Chil & John R. YatesAbstract
This paper presents the use of strain-life fatigue damage models to observe the cycle sequence effects in the wavelet-based fatigue data editing algorithm. This algorithm is called Wavelet Bump Extraction (WBE), which was developed to produce a shortened signal by extracting fatigue damaging events from the original signal with the retention of the original cycle sequences. Current industrial practice uses the Palmgren-Miner linear damage rule to predict the fatigue life or fatigue damage under variable amplitude (VA) loadings. Using VA loadings , however, this rule does not have load interaction accountability in the analysis.Thus,a more suitable approach has been identified for predicting fatigue damage of VA loadings, i.e. the Effective Strain Damage (ESD) model. In this study, the cycle sequence effect observation was implemented in both analytical and experimental works using the WBE extracted VA loadings. The study includes the comparison between the experimental and the analytical (using four strain-life fatigue damage models: Coffin-Manson , Morrow, Smith-Watson-Topper and ESD) fatigue damage. The smallest average in the fatigue damage difference was found when using the ESD strain-life model, suggesting the suitability of the this model for analysing VA fatigue loadings.
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5. Dual Boundary Element Method In Modelling of Fatigue Crack Propagation
Ahmad Kamal Ariffin Mohd Ihsan, Nik Abdullah Nik Mohamed & Fadhlur Rahman Mohd RomlayAbstract
This paper deals with the mod ling of fatigue crack propagation on a centre member bar using a dual boundary element method. The effects of life cycle to the multiple site fatigue crack propagation were studied. Analysis of stress intensity factor was performed by the deterministic approach using a dual boundary element method. The dual boundary element method was used to simplify the crack model through the numerical approach .The complex problems have been solved using the information from a boundary condition only. Next, the initial crack and life cycle of the structure have been predicted using probabilistic method which is Monte Carlo.The crack size and fatigue life were computed until failure of the structure. The failure analysis was performed by a linear elastic fracture mechanics. The scenarios of the fatigue crack propagation were given by an integration of both dual boundary element and Monte Carlo method. Therefore, fatigue life of multiple site crack structure can be predicted.
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6. Finite Element Based Life Prediction of A New Free Piston Linear Generator Engine Mounting
Md. Mustafizur Rahman, Ahmad Kamal Ariffin, Nordin Jamaludin & Che Hasan Che HaronAbstract
This paper presents the finite element based fatigue life prediction of a new free piston linear generator engine mounting. The objective of this paper is to assess the critical fatigue locations on the component due to loading conditions and also assess the damage tolerance design. This paper shows the effect of mean stress and the probabilistic nature of fatigue on the fatigue life. The finite element modeling and analysis have been performed using computer-aided design and finite element analysis software packages and the fatigue life prediction was carried out using commercial fatigue codes. Stress-life approach and strain-life approach are applied to predict the fatigue life of the free piston linear engine mounting. The result is a life contour, showing how long each area of a mounting will survive under defined loading conditions. The results are expected to show contour plots of fatigue life, and damage histogram at the worst or most damaging case. This paper shows the comparison between the stress-life approach and strain-life approach. From the results, it can be concluded that Morrow mean stress correction method has been found to give the most conservative results for strain-life method. SAE 1 045-450-QT and SAE 1 045-595-QT materials are considered in this study. It can be also seen that SAE 1 045-595-QT material gave consistently higher life than SAE 1 045-450-QT material for all loading conditions for both methods.
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7. Evaluation of Stress Intensity Factor Using Displacement Correlation Techniques
Abdulnaser A. Alshoaibi & Ahmad Kamal AriffinAbstract
The simulation of crack propagation relies on accurate computing of stress intensity factors (SIFs) at crack tips. Numerical methods are used to calculate the crack propagation path based on the computation of the crack incremental direction and stress intensity factors K1, K11 from the finite element response. This paper evaluates a nodal displacement method used for prediction of stress intensity factors.The method evaluated is the displacement correlation technique (DCT). The DCT is used when the singular element is present at the crack tip, and it uses the differential displacements for the adjacent nodes across the crack to compute the stress intensity factors. The crack path and its stress intensity factors are calculated in a specialised finite element program, using small crack increments.At each crack propagation step, the mesh is automatically refined based on automatic adaptive strategy that takes into account the estimation of stress analysis in two-dimension elastoplastic fracture. Crack has been modelled to propagate through the inter-element in the mesh. The crack is free to propagates without predetermine path direction. Maximum principal normal stress criterion is used as the direction criterion.
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8. Application of Monte Carlo Simulation for Free Piston Engine Cylinder Block Design
Nuraini Abdul Aziz, Ahmad Kamal Ariffin Mohd Ihsan, Mohd Jailani Mohd Noor & Nordin JamaluddinAbstract
This paper presents a stochastic simulation study to take account these uncertainties in a cylinder block structure of free piston engine. The computational stochastic structural mechanics and analysis allows a rational treatment of statistical uncertainties involved in structural analysis and design. It consists a stochastic simulation of the static analysis of the model structure where the analysis was executed from finite element software. The simulation study produces a data that identify the design input and output parameter that need to be optimised based on Monte Carlo method. By executing the design improvement analysis in the Simulation process, multiple solutions arrived from the target behaviour, which have been specified for the structure. For this cylinder model, it is found that from improvement design there is a significant r~uce in stress value of 18.2 MPa, modulus of elasticity for material “E2 of 160,200 MPa and increasing in modulus of elasticity for material 2, E2 of 71,1 00 MPa by controlling the target behaviour maximum displacement of the cylinder, Lmax .The correlations between these variables max ,were shown in the study, which allow designers to identify the strength of the relationship between variables and the uncertainties in the design.
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9. Numerical Modelling of Cyclic Stress-Strain Behaviour of Sn Pb Solder Joint During Thermal Fatigue
Mohd Nasir Tamin & Liew Yek BanAbstract
This study examines the cyclic stress-strain response of solder joints in a surface mounted electronic assembly due to temperature cycles. For this purpose, a three dimensional model of an electronic test package is analyzed using finite element method. The model consists of 92 solder joints arranged along the peripheral of a 24 x 24 solder array. The various different materials considered in the simulation are Si-die, 60Sn-40Pb solder alloy, Cu-traces, Cu6SnS intermetallics, FR-4 substrate and printed circuit board (PCB). The temperature and strain rate dependent plastic stress-strain curves define the viscoplastic response of the near-eutectic solder alloys. Orthotropic behavior of the FR-4 substrate and PCB is modeled. Other materials are assumed to behave elastically with temperature dependent material properties. Temperature loading of the package consists of an initial cooling down from the re-flow temperature at 183°C to 25°C followed by thermal cycling between -40°C to 125°C. Results of the analysis showed that the package warps with a magnitude of 93 um at 25°C after re-flow. ln this process, the critical solder joint accumulated an inelastic strain of 0.856 percent. Faster temperature ramp rate at 370°C/min (load case TR1) versus 33°C/min (load case T(1) resulted in 12 percent lower inelastic strain after completing 3 temperature cycles. However, the inelastic strain magnitude is achieved in a much shorter time.The shear stress-strain hysteresis loops display the largest strain ranges compared to other stress-strain components. The calculated shear strain range is 0.8 percent with the corresponding stress range of 34.0 MPa.
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10. The Design Improvement of Hip Implant for Total Hip Replacement (THR)
Solehuddin Shuib, Barkawi Sahari, Amran Ahmed Shokri & Chew Soon ChaiAbstract
Hip implants are artificial joints that are made of metal such as titanium or stainless-steel, and have long stems which penetrate deep into the femur canal to hold them in place. It is generally used when there is biological damage in human hip joint. Research also shows that the number of person that underwent this type of surgical operation is increasing every year especially for the elderly with the age group of 65 and above. The purpose of this project is to study improvements on hip implant and propose a design that mostly fulfills the aspects for designing a hip implant. There are many aspects to consider in designing hip implant such as stiffness, implant characteristic and size of the implant. Materials are also one of the most important aspects in designing a hip implant because it has a positive relation to the stiffness of the implant. The materials that commonly used are Titanium and Stainless-steel. The analysis was performed by using COSMOSWorks Software. It helped in studying the reliability, failure and optimum stress that the newly designed implant can withstand. In this project, the results showed that the factor of safety (FOS) of the implant is 1.4.
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11. Crack Propagation of Metal Powder Compact
Suraya Mohd Tahir, Ahmad Kamal Ariffin, Norhamidi Muhamad & Nik Abdullah Nik MohamedAbstract
Simulation of crack propagation in metal powder during the cold compaction process is presented in this paper. Based on a fracture criterion of granular materials in compression, a displacement based finite element model has been developed to simulate the fracture process in a multi level component made of iron powder. Estimation of fracture toughness variation with relative density is established in order to provide the fracture parameters as compaction proceeds.A finite element model with adaptive remeshing technique is used to accommodate changes in geometry during the compaction and fracture process, while friction between crack faces is modelled using the six nodes isoparametric interface elements. Two widely used yield criteria for powder compact, namely Mohr-Coulomb and Elliptical cap are used in the models. Different crack growth patterns obtained by using these two yield criteria are presented and compared in terms of the influence of shear stress and relative density distributions. Even though the crack starts at different compaction step and different crack patterns are obtained when different yield criteria is used, shear crack is predicted to starts in the region with lower relative density and higher shear stress in both models.
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12. Heat Transfer Analysis In Magnet Housing of Linear Generator Using Finite Element Method
Tulus, Ahmad Kamal Ariffin, S. Abdullah & Norhamidi MuhamadAbstract
This paper presents the heat transfer model of magnet housing in the linear combustion engine incorporating a combustion chamber and a kickback chamber.The heat transfer has been analyzed for the magnet and coils according to heat conducted from combustion and generated by current flowing through coils.By using the finite element method the problem has been analyzed using thermal analysis. The temperature distribution in magnet surrounding is considered. The results show that most of heat comes from the combustion chamber. The heat generated by the coils can rise the magnet temperature. The temperatures in the magnet are between 375 K and 382 K.
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13. Development of The Four-Cylinder Moving Mesh Model for A 1.6 Litre Four-Stroke Direct-Injection Engine
Shahrir Abdullah, Wendy Hardyono Kurniawan, Kamaruzzaman Sopian & Zulkifli Mohd NopiahAbstract
The design of a modern internal combustion engine requires the use of advanced analysis and development tools to carry out an in-depth investigation on internal combustion process and computational fluid dynamics (CFD) simulation by using high performance computers. In this work, the algorithm for moving or deformed mesh for a 1.6-litre four-cylinder four-stroke direct-injection engine has been developed.This type of mesh is required for transient simulation of fluid flow and combustion process inside the combustion chamber of an internal combustion engine.This mesh deforms with the movement of intake and exhaust valves as well as piston. Hence, the purpose of the work is to verify the moving mesh algorithm and to establish the correct mesh configuration at any crank angle. The simulation covers the full engine cycle consisting of intake, compression, power and exhaust strokes and the order of piston motion is set according to the firing order of the selected engine. The algorithm established defines events in which any of the designated engine component moves in terms of time and duration of occurrence. The verification of the algorithm was performed for the whole four-stroke cycle of 720° crank angles, where the positions of the intake valve, exhaust valve, cylinder and piston were updated accordingly with respect to crank angle. The finalised algorithm and mesh can be used to simulate the in-cylinder fluid flow and internal combustion process for the full engine cycle.
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14. Experimental Analysis of Noise And Back Pressure for Muffler Design
A. K. M. Mohiuddin, Mohd Rashidin Ideres & Shukri Mohd HashimAbstract
Exhaust noise of internal combustion engines is known to be the biggest pollutant of the present day urban environment. Proper design of the muffler is essential for the overall performance of the car. The main objective of this paper is to find the relationship between the back pressure and the noise level. Back pressure represents the extra static pressure exerted by the muffler on the engine through restrictions in the flow of exhaust gases. This needs to be kept to a minimum. The relationship between the noise and the back pressure is inversely proportional; lowering the noise level at the tip will result in high back pressure. However, this relationship is undesirable as the requirement is to have a quiet muffler with a small back pressure (ideal muffler). The design of the muffler chamber separation and arrangement is essential in determining the muffler characteristics. Some design considerations are proposed in order to come up with an optimum muffler design.The experimental data show a general shape of an average design of the muffler which would be the most suitable for the test car.
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15. Modelling and Simulation of Disc Brake Contact Analysis and Squeel
Abd. Rahim Abu Bakar, Huajiang Ouyang & Mohd Kameil Abdul HamidAbstract
Predicting disc brake squeal by means of the complex eigenvalue method has been a popular approach in the brake research community owing to its advantages over the dynamic transient method.The positive real parts of the complex eigenvalue reflect the degree of instability of the brake system and are thought to indicate the likelihood of squeal occurrence.This paper studies the disc brake squeal using a detailed 3-dimensional finite element (FE) model of a real disc brake. First, the FE model is validated through modal analysis both at component and assembly levels. Then, a number of possible structural modifications for suppressing unstable vibration are carried out. The effect of contact pressure distributions on squeal propensity is also investigated. Lastly, a plausible modification is proposed which should result in reduced positive real parts of the eigenvalues and hence produce better squeal noise performance.
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16. A Novelty Detection Technique for Machine Condition Monitoring Using S. O. M
M. L. DennisAbstract
This paper presents a novelty detection based method for machine condition monitoring (MCM) using Kohonen’s self-organising map (S.O.M.). As the fault data set is difficult to acquire in MCM problems, the method requires only the knowledge of normal condition data set. By exploiting S.O.M.’s ability of multi-dimensional mapping, the Euclidean distance between the S.O.M. and the data under test is used to discriminate anomaly from normal condition. A set of real world condition monitoring data is used to evaluate the method presented. Experimental result shows high accuracy and reliability of this method.
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17. Classification of Human Heart Abnormality Using Time-Frequency and Image Processing Technique
Fadzlul Rahimi Ahmad Bustami, Mohd Hanif Md. Saad, Mohd Jailani Mohd Nor & Bilkis Banu AzizAbstract
This paper describes heart abnormalities classification procedures utilising features obtained from time-frequency spectogram of ECG heart and image processing techniques. Enhanced spatial features of time-frequency spectogram were extracted and fed into a forward chaining expert system and the corresponding abnormalities were identified. A confidence factor is calculated for every classification result indicating the degree of belief that the classification is true. It was observed that the classification method was able to give 100% correct classification based on features that was extracted from data sets which were included in the knowledge base and data sets which were not included in the knowledge base.
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Vibration Fatige Analysis of Two-Stroke Free Piston Engine Using Frequency Response Approach
Md. Mustafizur Rahman & Ahmad Kamal AriffinAbstract

This paper describes a vibration fatigue analysis techniques to predict the fatigue life using the frequency response approach. The life prediction results are useful for improving the component design at a very early development stage. The finite element modeling and frequency response analysis have been performed using the finite element analysis software. In addition, the fatigue life prediction was carried out using both the time domain and frequency response methods. From the results, it is observed that the Dirlik method gives the best comparable results pseudo-static time domain approach with the frequency response techniques. This paper also describes how this technique can be implemented in the finite element environment to rapidly identify critical areas in the structure.This approach is capable of determining premature products failure phenomena. Therefore, it can reduce time to market, improve product reliability and customer confidence.

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19. Simulation of Flow-Mode Performance Due to Harmonic and Abrupt Excitation
Reiza Zakia Mukhlis, Nik Abdullah Nik Mohamed & Mohd Jailani Mohd NorAbstract
This paper discusses the performance of the suspension system that implements the flow-mode electrorheological damper in controlling the unwanted vibration caused by road surface irregularities. First, a mathematical model to determine damping coefficient of the damper was developed based on the fluid flow behavior in the gap between two electrodes.To evaluate the performance, the system is then simulated in two kind of road excitation; abrupt excitation and harmonic excitation. The performance is characterised by the level of ride comfort and road handling. The passenger ride comfort was evaluated by the force transmitted from the road to the passenger and by the vertical acceleration of the sprung mass, while the vehicle road handling was evaluated by the wheel hop and the amplification ratio. The result showed that the system can obtain the best compromise between road handling and ride comfort by adjusting the electric field strength that is applied to the damper.
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20. Identification of Driver’s Fittness Using Video Images and Steering Based Features
Ruzelita Ngadiran, Mohd Jailani Mohd Nor, Mohd Hanif Md. Saad & Yohan KurniawanAbstract
Driver’s Fitness is defined as a measure of a person’s physical strength, flexibility, and endurance to drive.Two main factors that lead to unfit driver are drowsiness and fatigue.This paper discusses features extracted from live video of drivers and steering wheel displacement to identify the relative state of driver’s fitness. A software based system, Driver’s Fitness Monitoring and Training System (DFMTS) was developed for to acquire the required data, extract the selected features and identify driver’s fitness. Fifteen participants were tested in an automotive simulator. Results obtained showed that there are identical patterns of the selected features found among the unfit driver’s.
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21. Kesan Kemodularan Reka Bentuk Terhadap Kebolehsenggaran Produk: Satu Kajian Kes (The Effects of Modularity Design on the Maintainability of A Domestic Product: A Case Study)
Dzuraidah Abd. Wahab, Kong Ee Ching & Tan Ai BoayAbstract
This paper reports the study on maintainability of a domestic product from the aspect of design modularity. In the study, the clustering technique was applied to the domestic product, an electric coffee maker in order to identify its functional components and the interactions between the components of the product. The service modes of the product were identified in order to ascertain the level of maintenance difficulty faced by the user. Guidelines in design for maintainability were applied during modifications to the existing design, focusing on three components in the main module of the product namely the cover of the base, the spraying unit and the cover of the strainer aperture. Result from the study has shown that considerations on design modularity and maintainability requirements at the early stage of product design, has enabled product maintenance  to be identified and planned in more systematic and effective manner. The proposed new design would certainly enhance the maintainability of the product.
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