Mohd Afendi Rojan
Thumbnail Image
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

Research Output

Filters

1
2
Reset filters

Settings
Now showing 1 - 2 of 2
Thumbnail Image
Publication

Microwave dielectric analysis on adhesive disbond in acrylic glass (Poly (Methyl Methacrylate)) at KU-band

2020-10-01 , Cheng Ee Meng , Mohd Afendi Rojan , Shahriman Abu Bakar , Zuradzman Mohamad Razlan , You K.Y. , Nashrul Fazli Mohd Nasir , Mohd Shukry Abdul Majid , Khairul Salleh Basaruddin , Mohd Ridzuan Mohd Jamir , Beh C.Y. , Khor Shing Fhan

A microwave dielectric spectroscopy for detecting adhesive disbonds between acrylic glass (aka Poly (methyl methacrylate)) was discussed. The adhesive bond was developed using epoxy resin and acrylate. The level of joint disbond can be quantified using Young Modulus. In this work, the strength of bond is affected by radius of air void within adhesive bond. A high-frequency electromagnetic wave propagated through two joint acrylic glass with acrylate and epoxy adhesive using waveguide adaptor WR90 in conjunction with professional network analyser. This electromagnetic wave is reflected and transmitted at the bond interface due to mismatch impedance at adhesive bond. The output is a dielectric properties that characterizes the bond interface. The increment of Young Modulus leads to increment of dielectric constant and loss factor for epoxy resin and acrylates, respectively.

View
No Thumbnail Available
Publication

Correlative investigation on dielectric-mechanical-morphological characteristic for kenaf-glass-hybrid fibers reinforced epoxy composite

2024 , Siti Mariah Mohd Yasin , Mohd Afendi Rojan , Wan Mohd Syafiq Wan Sulong , Hong Liang Ong , Nur Saifullah Kamarrudin , Shahriman Abu Bakar , Mariam Majid , Azman Ahmad , Kamarul Akmar Abdullah , Cheng Ee Meng

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.

View