Applied Mechanics and Materials Vol. 315

Abstract: Gas Metal Arc welding (GMAW) has shown potential, for Layered Manufacturing (LM) of metallic components, due to its inherent feature of high inter-layer and metallurgical bonding. Residual Stress induced warping is a major concern in a variety of LM processes, particularly those seeking to build parts directly without post processing steps. The temperature distribution and re-melting depth plays an important role in controlling residual stresses and distortion. This paper presents a 3D finite element based thermal model of a novel welding based deposition process as applied to LM. The model showed good agreement with experimental data. The results show that the process is not axis symmetric and a complete 3D model is required for accurate prediction of temperatures and deformation.

Abstract: This paper will explain a study of several printing process (screen printing, flexography, gravure and ink jet printing) for RFID antennas transponder. The potential of each process will also be investigated. A current sample of RFID is selected, and the antenna processes have been identified, and the comparison of antenna read range will be exhibited.

Abstract: The objective of this short review paper is to examine the practical applications of Total Productive Maintenance (TPM) in the manufacturing industry. In this short review, an attempt was made to critically discuss the previous literatures related to TPM with the other established quality initiatives in the manufacturing, such as Total Quality Management (TQM) and Just-In-Time practice (JIT). This literature review-based research revealed an important research gaps related to TPM. The significance role of TPM as an important complementary to either TQM or JIT initiative is observed not been well addressed in the available literatures. Most of the researches available investigate these initiatives separately, focuses on the other element rather than addressing on the significant role of TPM as one of the main thrust. The separate implementation of such quality initiatives in the manufacturing organization means the requirement of large scale human, financial and technical resources as well the associated problems of running competing project in the company. The outcomes from this review justify the needs of further research in the area of TPM integration with other available initiatives, to further enhance its methodology aimed at solidifying its philosophy towards more realistic practical applications.

Abstract: The physical properties of some materials used by local foundries were investigated with a view to assessing their suitability for use as low heat duty refractory bricks. The samples were collected from Malamai village, Gezawa Local Government, Kano state; they are Gezawa clay and Burji (Clay). The samples were crushed, ground, sieved and the chemical compositions were determined. The clay samples were treated separately as well as blended with Gezawa clay in different proportions and molded in to bricks. The bricks were dried and fired to 1100. Test for refractoriness, thermal shock resistance, linear shrinkage; bulk density, porosity and compressive strength were carried out on each of the specimen. Burji blended with 50% to 90% Gezawa clay gave improved thermal shock resistance with a refractoriness of 1300 and hence could be used for non ferrous melting cupolas.

Abstract: This paper explains about the evaluation of intake air flow, volumetric efficiency and noise of a motor-driven engine that used an adaptive valve lift and timing mechanism (AVLT) on one intake valve. This system is developed with an aim to produce a more powerful engine through variable valve timing and lift technique. The system made the valve lifts higher without increasing the valve lift duration. Therefore, a dynamic valve lift profile with respect to the engine speed can be achieved thus varies the input and output of an engine. As a result of applying the AVLT on a motor-driven engine, the engine noise, emission noise and the mass air flow entering the engine cylinder was increased. When AVLT is employed to a maximum lift, the mass air flow of default intake valve lift was improved within a range from 8% to 46.64% in 500 rpm to 2000 rpm speed range. Maximum lift produced engine noise within a range of 2.57% to 18.13% higher than the default lift throughout all speed. Also, maximum lift produced emission noise within a range of 2.47% to 19.19% higher than the default lift throughout all speed. The product of this research will be useful to optimise the height and timing of the valve lift and the AVLT mountings on the engine head during operation thus improves the engine performance, fuel economy, emission levels and reduced noise of a modified engine.

Abstract: Sustainability concern has brought the idea of exploring the possibility of using water as the hydraulic medium to transfer energy. The abundant resource of water, and its characteristic involving hygiene, safety and low maintenance cost provides a fascinating perspective of choosing water over hydraulic oil, due to concerns over oil disposal, contamination, costly maintenance and flammability. However, in contrast, its low boiling temperature, low viscosity, and simple molecular structure could pose danger to the operation of the hydraulic system. In order to identify these limitations, an experimental study is carried out to explore the effect of water hydraulic system. A test rig of scissor lift is fabricated and put into test by replacing the hydraulic oil with reverse osmosis water. It is found that the water hydraulic scissor lift managed to lift up to 400 kg of load, with workable water temperature of 41.4°C.

Abstract: The implementation of Classical Cascade Controller for the purpose of controlling various type of engineering appliances has been vastly utilized by control engineer community. Cascade controller provides a simple structure of controller but yet functional and have the ability to satisfy the control design requirement. In general, the controller consists of two loops, namely velocity loop and position loop. This paper is focused on the fundamental aspect on how to analyzed the close loop behaviour for both velocity and position loop and to extract the mathematical formulation of the controller. The outcome from this paper which is in the form of mathematical formula is useful and very significant in order to validate the theoretical result with the simulation result. To be more precise, the result from this research work are in the form of transfer function for both velocity and position loop of the position output, position error, dynamic stiffness of the controller and the damping ratio of the system which is in this case the XY Table Ballscrew drive system.

Abstract: Homogeneous charge compression ignition (HCCI) combustion, when applied to a gasoline engine, offers the potential for a noticeable improvement in fuel economy and dramatic reductions in NOx emissions. In this study, Computational Fluid Dynamic (CFD) is used coupled with detailed chemical mechanism (38 species and 69 reactions) for simulation of HCCI combustion of iso-octane and transitional flow inside the combustion chamber of a 2-stroke engine. Results show that increasing the overall gas temperature significantly advances the HCCI combustion timing. Concerning the equivalence ratio, by increasing it the ignition timing has been advanced and the maximum cylinder pressure has been increased. When equivalence ratio increases to more than 0.5 , NOx emissions significantly increases and go beyond 1000 [ppm].

Abstract: Value Engineering (VE) is important tool to company in global market competition to providing a demand. VE process can provide for company continued growth and prosperity if applied properly. VE is defines as the systematic application of recognized techniques, which identify the function of product or service, establishes a monetary value for that function and provides the necessary function reliability at the lowest overall cost. This paper will presents a process on how to apply VE tools in manufacturing company. Therefore, we would like to study the application of VE approach method and at the same time investigating how much cost reduction can be done. The function of product will be defining and cost reduction is suggested by proposing alternative method to achieve that function. However the function quality is never degrading. The result is showed that 60% cost reduction can be proposed.

Abstract: Due to creating health problems for human by using vehicles in long term, seat suspension design is important especially in off-road vehicles. Recently, intelligent methods are focused by researchers for optimization problems. In this paper, artificial neural network biodynamic model (ANNBM) was used to simulate human body responses to the vertical direction and seat suspension was optimized to reduce vibration transmitted from seat to lower lumbar. Particle Swarm Optimization (PSO) was employed for this purpose. The results of simulation shows 0.6 seat to spine vibration transmissibility (SST), and the efficiency of suspension seems good to remove unwanted vibration.