Masniezam Ahmad
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Preferred name
Masniezam Ahmad
Official Name
Masniezam, Ahmad
Alternative Name
Ahmad, Masniezam H.
Ahmad, M.
Main Affiliation
Scopus Author ID
56272606200
Researcher ID
IXE-4791-2023

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  • Publication
    Modification of the design of circular thin-walled tubes to enhance dynamic energy absorption characteristics: experimental and finite element analysis
    (IOP Publishing Ltd., 2020)
    Masniezam Ahmad
    ;
    Khairul Azwan Ismail
    ;
    Mohd. Hazwan Mohd. Hanid
    ;
    Fauziah Che Mat
    ;
    A M Roslan
    A thin-walled tube is an energy absorber device that functions to dissipate kinetic energy into another form of energy during impact. The design of thin-walled tubes is a significant factor which affects to the energy absorption characteristics. This paper provides a comparative study between the original thin-walled tube designs and several modified tube designs that have been proposed. The main objective is to improve the energy absorption characteristics, such as energy absorption capacity, initial peak load, specific energy absorption (SEA) and crush force efficiency (CFE). Throughout this research, aluminium alloy AA6061-T6 has been used as the material for all tubes. For comparison, all of the tubes are developed with a circular shape with the same diameter, thickness and length. In addition, they are also impacted at the same kinetic energy under dynamic axial loading. Validated LS-DYNA finite element (FE) models have been used to simulate the impact of the thin-walled tubes. Compared to the original tube design, the modified tubes have improved energy absorption characteristics. A conical tube with a flat end cap was identified as the best performing tube among the modified tubes because it had the lowest initial peak load, a moderate energy absorption capacity and an excellent CFE and SEA. The findings from this study can be used as a guidance in designing thin-walled structure.
  • Publication
    Computational Fluid Dynamics Analysis of Varied Cross-Sectional Areas in Sleep Apnea Individuals across Diverse Situations
    ( 2024-01-01)
    Wan Mohd Faizal Wan Ab Rahim
    ;
    Khor Chu Yee
    ;
    Mohamad Suhaimi Shahrin
    ;
    Muhamad Nur Misbah
    ;
    Mohd. Hazwan Mohd. Hanid
    ;
    Masniezam Ahmad
    ;
    Mohd Haidiezul Jamal Ab Hadi
    Obstructive sleep apnea (OSA) is a common medical condition that impacts a significant portion of the population. To better understand this condition, research has been conducted on inhaling and exhaling breathing airflow parameters in patients with obstructive sleep apnea. A steady-state Reynolds-averaged Navier–Stokes (RANS) approach and an SST turbulence model have been utilized to simulate the upper airway airflow. A 3D airway model has been created using advanced software such as the Materialize Interactive Medical Image Control System (MIMICS) and ANSYS. The aim of the research was to fill this gap by conducting a detailed computational fluid dynamics (CFD) analysis to investigate the influence of cross-sectional areas on airflow characteristics during inhale and exhale breathing in OSA patients. The lack of detailed understanding of how the cross-sectional area of the airways affects OSA patients and the airflow dynamics in the upper airway is the primary problem addressed by this research. The simulations revealed that the cross-sectional area of the airway has a notable impact on velocity, Reynolds number, and turbulent kinetic energy (TKE). TKE, which measures turbulence flow in different breathing scenarios among patients, could potentially be utilized to assess the severity of obstructive sleep apnea (OSA). This research found a vital correlation between maximum pharyngeal turbulent kinetic energy (TKE) and cross-sectional areas in OSA patients, with a variance of 29.47%. Reduced cross-sectional area may result in a significant TKE rise of roughly 10.28% during inspiration and 10.18% during expiration.
      1  25
  • Publication
    Energy Absorption Characteristics of Thin-Walled Tubes Filled with Rice Husk and Kenaf Fibers
    (Universiti Malaysia Perlis, 2024-12-02)
    Masniezam Ahmad
    ;
    Khairul Azwan Ismail
    ;
    Fauziah Che Mat
    ;
    Mohd. Hazwan Mohd. Hanid
    ;
    Ahmad Azraai Abd Aziz
    This study investigates the energy absorption characteristics of thin-walled tubes filled with rice husk and kenaf fibers when compressed under axial compression. The aim of this study is to evaluate the crashworthiness parameters such as energy absorption (EA), initial peak load (IPL), crush force efficiency (CFE) and specific energy absorption (SEA). Experimental results show that tubes filled with rice husk and kenaf exhibit significant improvements in overall energy absorption compared to empty tubes. However, while both fillers enhanced EA, the SEA values were lower than predicted. Thus, it is suggested that further optimization, such as adjusting filler density or exploring hybrid filler combinations, could improve crashworthiness. This study highlights the potential for rice husk and kenaf fibers as sustainable filler options for lightweight, impact-resistant designs in automotive, aerospace, and other engineering applications, with opportunities for improvement in future research.
      3  1