Papers by Author: Ruslizam Daud

Abstract: Most of Napier grass industry in Malaysia is labored in small and medium scale. Therefore, the harvesting works are done manually by man power using conventional equipment such as sickle and machete. However, there are some efforts made to design the low cost equipment in assisting this Napier grass harvesting works. The aim of this study is to compare the Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) performance in order to evaluate the certain body parts condition during harvesting works by using conventional equipment and innovation machine assisted. Based on survey, conventional harvesting method might increase the risk of low back pain (LBP) due to repetitive stooping posture. Furthermore, the back biomechanical load and force impact were also not handling wisely. The objective of this study is to prove that the usage of machine during harvesting works might improve the body posture especially on stoop level condition. Based on results, the overall RULA and REBA score are excellently improved as well as trunk position which is depicts the stooped level condition. Hence, the innovation of harvest machine could contribute to the Napier grass industry especially on small and medium entrepreneur.

Abstract: Bone fracture can occur in all parts of human skeletal cortical bone including phalanx bone of finger bone. Sometime, it leaves permanent damage and a long period of recovery. This situation can be prevented if we understand the mechanics and the process of the bone fracture. This study aims is to evaluate stress shielding induced by crack interaction using a simple model on Linear Elastic Fracture Mechanics (LEFM). Numerical simulation had been carried out in this study to understand the stress shielding induced by crack interaction. The results revealed that the interaction of two cracks is directly proportional to the stress intensity factor (SIF) magnitude at crack tips. Finally, as the crack-to-width ratio increase and the strain energy release rate also increased.

Abstract: Solder joints are exposed to drop impact, vibration loading, bending, and twisting of PCBs. Study on this matter will lead to prediction of fracture load, prevalent fracture mode, exact joint interconnect size and life of joints under brittle and fatigue failure. This paper presents a finite element modeling of intermetallic compounds solder joints failure based on displacement extrapolation method. Based on conceptual FE model of intermetallic IMC solder joints, this paper present the full model of IMC model for intermetallic Mode I and Mode II fracture prediction.

Abstract: Solder joints failure due to thermal loads and mechanical loads is a significant reliability concern in electronic devices. From literatures, little attention is paid to the development of methods on predicting fracture behavior of solder joint under mixed-mode loading. This paper presents a finite element modeling of intermetallic compounds solder joints failure based on displacement extrapolation method (DEM). Conceptual study on single edge crack on intermetallic IMC solder joints is presented.

Abstract: The use of adhesive structural in joining application offers the great demand due to its many advantages such as lightweight structures and flexible design. However, moisture provides significant problem and adverse effect on degrading the adhesive. The strength of the adhesive reduces because mechanical properties are known to reduce also with moisture environment. Therefore, this paper discusses about the adhesive T-joint test on specimen within moisture condition and specimen without moisture, at room temperature. Additionally, this study also analyses the failure stress when load is applied for both exposed conditions. Bulk specimens are compressed at room temperature, specimen without immersing in hot water, RT and specimen with immersing in three hot water conditions 80°C, 90°C, and 100°C at a constant time of 15 minutes. The adhesive of a 1.0mm thickness has been set for T-joint tensile test. Compression test revealed that mechanical properties of Young’s modulus decreased with the increase of water temperature. Experimental results indicated that the failure stress of adhesive T-joint at room temperature and 90°C was higher compared to that of specimen soaked in 80°C and 100°C of hot water. The behaviour of adhesive joint tests under static loading analysis of experiments and the finite element analysis using ANSYS 14.0 software have shown good agreement.

Abstract: This study evaluates the effect of temperature upon adhesive properties and behavior of adhesively bonded T-joint. Finite element analyses established the effect of this parameter on the durability joint and stress distribution within the adhesive layer. A series of temperatures and stress analyses using finite element analysis (FEA) has been conducted in the T-joint configuration for this purpose. The parametric studies on the FE model revealed that stress distributions are sensitive to the changes in adhesive properties due to changes in temperature. In general, stresses were reduced with changes in the temperature which resulted in the ability of the adhesive layer to undergo plastic deformation.

Abstract: This paper describes a study on the effects of heat treatment on the microstructure, hardness and wear of aluminum alloys 332 (AlSi₉Cu₃Mg). The solution treatment was performed at 500°C for 5 hours and then quenched in water at room temperature. Aging was performed at 170°C for 2 hours. The findings revealed that after a full heat treatment, the structure of the eutectic silicon formed toward fragmentation and spheroidization, and the silicon particles became coarse (look-like rounded). Hard intermetallic compound (Mg₂Si) appeared on the microstructure after the aging treatment completed. Compared to the as-cast, the hardness of the alloys has improved to 44.84%, and the wear rate of the solution treatment had decreased to 26% while the aging treatment showed a deterioration of 79.42%. The study concludes that aging treatment improves the hardness of AA332 alloys and enhanced the wear resistance of the substance.

Abstract: Fabrication of an impedance tube for measuring sound absorption coefficient is presented in this paper. Transfer-function method is chosen for the sound absorption analysis. The impedance tube is designed and fabricated in accordance with ISO 10534-2. The tube is made from brass with diameter of 114.3 mm and length of 1.42 m. It is designed for the frequency range 60 Hz to 1800Hz. Three microphone positions are installed to achieve the frequency range with a single tube. The theoretical background of transfer-function method between two microphones is discussed. Initially, impedance tube is characterized by the measurement without testing material in the tube. Micro-perforated panel (MPP) with 50 mm and 100 mm of cavity depth are used for measurement. The sound absorption coefficient measurement of the MPP is compared with theory and good agreement is achieved. Various problems related to design and construction is addressed and the optimal configuration is presented.

Abstract: Solar energy is a viable renewable energy source, and photovoltaic technology has mature significantly in recent years. To maintain the operating efficiency of photovoltaic system, heat must be remove from its surface, thus lead to development of photovoltaic/thermal system. This paper identify several key design criteria as well as heat transfer enhancement methods that is currently existed, and some future work is proposed to optimize the system.

Abstract: Wind turbine is a device used to convert kinetic energy into electrical energy. Generally, wind turbine could be classified as horizontal axis and vertical axis wind turbine, depending on its axis of rotation. Two major factors affecting wind turbine performance are wind speed and aerodynamic design. While wind speed is depending on the location and weather, aerodynamic design of the wind turbine could be improved and optimized to enhance the wind turbine efficiency. This paper summarized few such design with particular attention on output power analysis as well as analysis tools development, for both type of wind turbine.