Now showing 1 - 4 of 4
  • Publication
    The Effect of Dry and Wet Condition on the Mechanical Properties of Hybrid Single Lap
    The aim of this study is to investigate the strength and mechanical behaviour of similar and dissimilar materials AA7075/E-glass single lap joint. The specimen radially in stack with Araldite epoxy adhesive and mechanical fasteners of Huck bolt with the bondline length of 64 mm for different joint configurations; bolted, bonded and hybrid. The investigation was conducted under two different conditions of dry and wet of 55°C for long water immersion of 120 days. The effect of moisture was defined in hybrid joints as combination of adherend and bonding materials. The tensile test with a speed rate of 1 mm/min was conducted for both condition using 100 kN load cell until total failure of specimen. The experimental results were plotted into load displacement and stress strain curve for each environment. In addition, failure mechanism of the specimens was detected in which occurred at adhesive and Huck bolt.
  • Publication
    Biogas production from the paddy straw pretreated with Sodium Hydroxide and co-digestion with cow manure
    ( 2024-03) ;
    Muizz Zahari
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    ;
    Abdul Syafiq Abdul Syukor
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    Paddy straw waste (PS) is an organic waste that is disposed in open land after preparation of rice harvest that is generated in equal or greater quantities than the rice itself. Generally, it is disposed in open land, which increases anthropogenic gases. Converting it into useful energy or value-added products may reduce disposal problems and anthropogenic activity. In this study, PS with different treatments of sodium hydroxide (NaOH) at 2, 4, 6 , 8 and 10% was co-digested with cow dung (CD) for obtaining biogas by anaerobic digestion. For this purpose, PS was mixed with CD at different proportions, namely 50:50, 40:60, 30:70, 20:80, and 0:100 percentages on a mass basis, the samples were used in five different anaerobic digesters. The samples were kept in different anaerobic digesters for the study. The effect of important input parameters like pH and Carbon to Nitrogen (C/N) ratio on the biogas production was studied. Maximum biogas production was obtained from the co-digestion of the substrate containing 30% ps and 70% Cd for a digestion time of 20 days, and d3 shows a max pH value of 7.16. Further, the biogas collected from the digesters was characterized to ensure suitability for use as a renewable fuel. Furthermore, the digested slurry was also analyzed for its use in agriculture. The results are presented in this paper.
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  • Publication
    Environmental effect on short-beam composite under three-point bending test
    The effect of moisture, water absorption on a single short span beam of glass fiber reinforced polymer (GFRP) was examined under room temperature, 27°c. The aim of the study is to investigate the mechanical properties of composite under wet condition. The composite were cut into rectangular shape with a dimension of 78 mm long, 26 mm width and 3.5 mm depth. The moisture content of eight specimens was experimentally reduced as the glass fiber content increased. In this investigation, the flexural strength and modulus of composites were determined throughout the three-point bending test. The specimens were rigged up horizontally as supported beams and loaded vertically at the geometric center. Thus, the results were developed into loading versus deflection and relationship for each specimen. The samples were considered to have failed when the curves were in steady decline section. Failure mechanisms were observed in categories; face yield, core yield and fiber tear.
      1  24
  • Publication
    Correlative investigation on dielectric-mechanical-morphological characteristic for kenaf-glass-hybrid fibers reinforced epoxy composite
    (Semarak Ilmu Publishing, 2024)
    Siti Mariah Mohd Yasin
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    ; ;
    Hong Liang Ong
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    ; ; ;
    Azman Ahmad
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    Kamarul Akmar Abdullah
    ;
    In recent years, there are many applications where synthetic fibers and natural fibers are used as reinforcing materials in composites, such as the automotive and aerospace industries, the medical industry, and the construction industry. While these hybrid fibers effectively enhance mechanical and electrical properties, research into electrical characteristics remains inadequate and is an ongoing endeavor. In this work, synthetic woven glass fibers and natural woven kenaf fibers were used to fabricate composite materials by vacuum infusion technique. The dielectric properties of three different substrates, glass fibers, kenaf fibers and glass/kenaf fibers reinforced epoxy composites were investigated at 0° orientation. The ENA Network Analyzer was used to measure dielectric properties in a wide microwave frequency range. The substrates were single-joint overlapped with an adhesive and then mechanically tested. The shear strength of the joint as a function of strain, was tested using a Shimadzu universal testing machine. Visual inspections were performed to determine the failure modes of the composites. The dielectric constant and loss factor of the glass fiber composite were the highest, while the kenaf fiber composite had the lowest value. When a small amount of glass fibers is incorporated into kenaf fibers, which is called a hybrid composite, the polarization increases and the mechanical strength also increases compared to the kenaf fiber composite. Scanning electron microscopy (SEM) of the fractured tensile tests was performed to understand the nature of the interfaces between glass, kenaf and matrix. The kenaf/matrix interface was heterogeneous but exhibited voids, resulting in low dielectric properties and mechanical strength. By inserting a small amount of glass fibers, the hybrid with kenaf fibers improve the dielectric constant by 20.7% and the dielectric loss factor by 27% compared with the kenaf fiber composite. The results also show that the composites exhibit a correlation between the dielectric properties, tensile strength, and the morphological nature of the interfaces.