Mohd Afendi Rojan
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Preferred name
Mohd Afendi Rojan
Official Name
Mohd Afendi , Rojan
Alternative Name
Afendi, Mohd
Rojan, M. Afendi
Afendi Rojan, M.
Afendy, M.
Rojan, M. A.
Mohd Afendi, R.
Afendi, M.
Main Affiliation
Scopus Author ID
57188766103
Researcher ID
GQR-0248-2022

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Fatigue life investigation of UIC 54 rail profile for high speed rail

2017-10-29 , Gurubaran Panerselvan , Mohd Afendi Rojan , Nur Fareisha M. A. , Mohd Shukry Abdul Majid , Haftirman I. , Md. Tasyrif bin Abdul Rahman

This study is to investigate the fatigue life of high speed rail in Malaysia. This paper describes about the experimental and simulation analysis investigation on fatigue life of rail profile UIC 54 using bulk specimen according to ASTM E 466-15 standard. The Fatigue life testing was performed in the fatigue testing machine (Instron 8800) 100 kN. Meanwhile, the fatigue life analysis was performed in ANSYS Workbench 14.5. Furthermore, the stress levels for experimental testing were applied as 16.7%, 25%, 35%, 50%, 58.3%, 66.77% and 75% with machine frequency of 20 Hz. Apart from that, the total fatigue life cycles for rail profile UIC 54 were acquired from both experimental and simulation. The fatigue life S-N curves were plotted and validated with the results of the simulation analysis with experimental results.

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Feasibility Study of Microwave Welding of Polypropylene Using Silicon Carbide Nanowhiskers as Microwave Susceptor

2023-01-01 , Foong P.Y. , Voon Chun Hong , Lim Bee Ying , Teh P.L. , Mohd Afendi Rojan

Currently, welding is the most efficient way for joining of plastic. Due to its rapid heating, efficiency in term of time and energy, and ability to be applied on components of any shape, microwave welding stands out from other welding methods. Additionally, SiCNWs was proposed as the microwave susceptor for the microwave welding of thermoplastic in this work due to its high dielectric loss and biocompatibility. To produce microwave welded joint, SiCNWs was first mixed with acetone to obtain a SiCNWs suspension. After that, SiCNWs was drop casted onto the targeted area of PP, allowed to dry and then microwave irradiated. In this work, the microwave heating time studied ranged from 15 s to 20 s. SEM and single lap shear test were used to characterise the microwave welded joint. From the findings, the tensile strength increased as the microwave heating duration increased from 15 s to 18 s, due to formation of SiCNWs/PP nanocomposite welded joint layer with increasing thickness. Yet, when the microwave heating time was prolonged to 20 s, the tensile strength decreased to 0.85 MPa. Besides, a void was observed at the welded joint and it is believed that the presence of void causes the welded joint to weaken when force is applied. Under properly regulated of microwave heating time, a strengthened nanocomposite welded joint can be produced which demonstrate great promise in plastic welding.

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Effects of fibre loading and moisture absorption on the tensile properties of hybrid Napier/glass/epoxy composites

2017-10-29 , Zikri M. , Mohd Ridzuan Mohd Jamir , Mohd Shukry Abdul Majid , Mohd Afendi Rojan , Khairul Salleh Basaruddin

The primary objective of this study was to investigate the effect of moisture absorption on the mechanical degradation of hybrid Napier/glass-epoxy composites. The hybrid Napier/glass-epoxy composites plates were produced by the vacuum infusion method using epoxy resin as a matrix. The hybrid composite specimens were tested after following 50 h of water immersion. The moisture content decreased as the glass fibre content increased. The wet and dry hybrid composite samples were subjected to tensile tests. The incorporation of the glass fibre into the Napier grass fibre-epoxy composites enhanced their tensile strength and tensile modulus. The tensile strength and tensile modulus of the hybrid Napier/glass-epoxy composites (24/6-70 vol%) were 43 MPa and 3.2 GPa, respectively. However, the tensile strength and tensile modulus properties highly degraded under wet conditions.

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Effect of loading protocol on the mechanical properties of 316L stainless steel

2021-10-25 , Heng S.H. , Azmi M.S.M. , Mohd Afendi Rojan , Mohd Sani Mohamad Hashim , Mohd Nasir Ayob , Abdul Halim Ismail , Muhamad Saifuldin Abdul Manan , Abdullah S.

Two types of loading protocol, i.e., monotonic loading and cyclic loading, were compared to investigate the effect on the mechanical properties of 316L stainless steel. The specimen used is a dog-bone specimen in accordance with ASTM E8 and ASTM E606 standard. For cyclic loading, the multiple-step method is used to obtain the hysteresis loop of the material. A total of 13 strain amplitude conditions had been carried out, ranging from 0.05%-0.65%. The stress-strain curve shows that the cyclic stress-strain curve is higher than the monotonic stress-strain curve due to the cyclic hardening behaviour in the 316L stainless steel. The cyclic hardening behaviour increases the ultimate tensile stress of the material. However, when the material gains its strength through cyclic hardening, the ductility in the material will decrease.

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Convergence and stress analysis of the homogeneous structure of human femur bone during standing up condition

2017-09-26 , Izzawati Basirom , Ruslizam Daud , Mohd Afendi Rojan , Mohd Shukry Abdul Majid , Noor Alia Md Zain

Finite element models have been widely used to quantify the stress analysis and to predict the bone fractures of the human body. The present study highlights on the stress analysis of the homogeneous structure of human femur bone during standing up condition. The main objective of this study is to evaluate and understand the biomechanics for human femur bone and to prepare orthotropic homogeneous material models used for FE analysis of the global proximal femur. Thus, it is necessary to investigate critical stress on the human femur bone for future study on implantation of internal fixator and external fixator. The implication possibility to create a valid FE model by simply comparing the FE results with the actual biomechanics structures. Thus, a convergence test was performed by FE model of the femur and the stress analysis based on the actual biomechanics of the human femur bone. An increment of critical stress shows in the femur shaft as the increasing of load on the femoral head and decreasing the pulling force at greater trochanter.

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Derivation and validation of heat transfer model for Spark-Ignition engine cylinder head

2023-05-05 , Hassan M.A.S.M. , Zuradzman Mohamad Razlan , Shahriman Abu Bakar , Anas Abdul Rahman , Mohd Afendi Rojan , Wan Khairunizam Wan Ahmad , Ibrahim Z. , Ishak A.A. , Mohd Ridzuan Mohd Jamir

The valve train is located in the engine cylinder head, which has various operational heat transfer mechanisms to accommodate the combustion process. Most heat transfer studies in this area have only addressed medium-to high-power vehicles at a single running speed. In this study, a model of an air-cooled underbone motorcycle valve, valve seat, and engine cylinder head was tested to determine the thermal characteristics using actual engine operating conditions at low, medium, and high engine speeds. One-dimensional thermal simulation analyses were conducted to obtain the instantaneous heat-transfer coefficients of an actual engine. The average thermal value was determined as the boundary condition in the three-dimensional thermal analysis. A three-dimensional model was prepared using the ANSYS commercial computational fluid dynamics software package. The results show that as the engine speed increases, so does the thermal load toward the component in the engine cylinder head. The strongest temperature regions were concentrated around the combustion face. The exhaust valve held most of the heat, with the valve neck recording the highest temperature. For the intake valve, the combustion face registered the majority of the heat. The heat flux intensity was gathered in the contact surface area between the valve and its seat, between the valve stem and guide, and between the stem guide and tip section. A thermal survey was used to validate the three modelling results for two separate engine datasets. The cumulative relative errors for intake and exhaust valve seats for low engine speeds were 3.73% and 0.17%, respectively. The intake and exhaust valve seats had cumulative relative errors of 4.12% and 0.70%, respectively, at intermediate speeds. This methodology provides valuable information for analysing the heat characterisation of air-cooled engines. It can also be a useful blueprint for the automotive industry and other researchers involved in thermal measurements.

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Design Optimization of Exhaust Manifold's Divergence Characteristics in Enhancing High-End Power in 115cc SI Engine

2022-01-01 , Murali R. , Shahriman Abu Bakar , Zuradzman Mohamad Razlan , Ishak A.A. , Ika Syahira Abdullah , Mohd Afendi Rojan , Ibrahim Z. , Wan Khairunizam Wan Ahmad

The exhaust system especially the exhaust manifold is an essential component that affects the performance of the Spark Ignition (SI) engine. The critical factor inside the exhaust system that affects the engine's performance is backpressure. Backpressure is known as the difference between maximum pressure in the exhaust system and atmospheric pressure. Based on previous studies, it was found that an un-optimal exhaust manifold's design leads to higher backpressure that reduces the performance and the fuel efficiency of the SI engine. This research aimed at enhancing the high-end power of the 115cc SI engine by optimizing the exhaust manifold's divergence characteristics through 1D engine analysis. S/N ratio analysis was used through Taguchi's method as a tool to conduct the design optimization. From the analysis, it was found that the optimal exhaust manifold's divergence configuration improved the mean brake power by 4.67% at high-end engine speed. It is expected that the optimal exhaust manifold's divergence configuration could also improve the engine's brake torque and fuel efficiency which could directly reduce the carbon footprint to the environment.

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A study on the significance of exhaust manifold’s bending angle to the brake torque of 115cc SI engine

2023-01-01 , Murali R. , Shahriman Abu Bakar , Mohd Afendi Rojan , Zuradzman Mohamad Razlan , Azizul A.I. , Rani M.F.H. , Mohd Ridzuan Mohd Jamir , Sunan S. , Ali M.H.A. , Ramasamy G. , Hisham M.H.N.

The exhaust manifold is a crucial component of the exhaust system in any SI engine, responsible for efficiently expelling combustion products. However, when the exhaust manifold's design is suboptimal, it leads to negative consequences for the engine's performance due to the presence of backpressure. Backpressure refers to the difference between maximum exhaust pressure and atmospheric pressure. An increase in backpressure decreases the overall performance and fuel efficiency of an SI engine. This study aimed to investigate the bending angle characteristics of the exhaust manifold and the brake torque of the 115cc SI engine using 1D engine analysis. The relationship between the exhaust manifold's bending angle characteristics and the brake torque was analysed using Analysis of Variance (ANOVA) with a p-value of less than 0.05, while the validation with experimental data showed a maximum error of 6.62. In the previous research, it was noted that a lower bending angle leads to better performance. However, the current results indicate that out of the three bending angles considered, having one of them yields the most substantial enhancement in brake torque. The optimized bending angle configuration obtained from the analysis increased the mean brake torque by 0.011 Nm (0.14%). Consequently, this study enhances the average brake torque through the optimal bending angle characteristics of the exhaust manifold. The study's objective aligns with Sustainable Development Goal (SDG) 9: Industry, Innovation, and Infrastructure, as the improved performance achieved through an optimal exhaust manifold design configuration is expected to promote domestic technology development.

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Formation of polypropylene nanocomposite joint using silicon carbide nanowhiskers as novel susceptor for microwave welding

2023-05-01 , Foong P.Y. , Voon Chun Hong , Lim B.Y. , Teh P.L. , Mohd Afendi Rojan , Subash Chandra Bose Gopinath , Mohd Khairuddin Md Arshad , Nor Azizah Parmin , Low F.W. , Ruslinda A. Rahim , Uda Hashim

Up to present, no study has reported on the use of silicon carbide nanomaterials (SiCNMs) as susceptor for microwave welding of thermoplastics. Therefore, in this study, silicon carbide nanowhiskers (SiCNWs) was attempted as the microwave susceptor for the microwave welding of polypropylene (PP). It was observed that SiCNWs are capable of absorbing microwave and converting them into heat, leading to a sharp increase in temperature until it reaches the melting point of PP substrates. The microwave welded joint is formed after the molten PP at the interface between PP substrates is cooled under pressure. The effect of microwave heating duration and solid loading of SiCNWs suspension was studied and reported. The formation mechanism of SiCNWs reinforced PP welded joint was proposed in this study. With these remarkable advantages of microwave welding and enhanced mechanical properties of the welded joint, it is believed that this study can provide a new insight into welding of thermoplastic and material processing through short-term microwave heating.

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The Effect of Process Temperature and Holding Time on Weldability in Diffusion Welding of Duplex Stainless Steels and Marine Grade Steels for Oil and Gas Pipes

2022-01-01 , Baharudin B.A. , Mustapha M. , Azman M.A. , Shamsuddin A.N. , Ismail A. , Tuan Anuwa T.M.N. , Ab Rahman F. , Ayob F. , Hamid D.A. , Mohd Afendi Rojan

Diffusion welding is done on specimens of duplex stainless steel and low carbon steel under varied temperature and holding time. The specimens were clamped using jigs and pre-pressed at 10 MPa and heated in a furnace. Impact test were performed on the joined samples. The effect of process temperature and holding time on the impact strength of the diffusion welds were observed. The impact strength of the joints was examined, and the highest value of 0.9 J is obtained at a temperature of 1050 °C and holding time of 240 min.

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