Ahmad Humaizi Hilmi
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Ahmad Humaizi Hilmi
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Ahmad Humaizi, Hilmi
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Hilmi, Ahmad Humaizi
Hilmi, A.
Humaizi, Ahmad
Hilmi, A. H
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Scopus Author ID
57193311438
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W-1988-2019

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Current issues related to anthropometry in engineering

2022 , Ahmad Humaizi Hilmi , Asna Rasyidah Abdul Hamid

Anthropos and Metrikos both mean "human" in Greek, which is where the term anthropometry comes from. Anthropometry is employed in a variety of fields, including apparel and textile design. For anthropometric evaluations, a current, thorough, and community-specific anthropometric normative-reference standard is necessary. In health care, ergonomic design is utilised to reduce pain and illness. Misalignments between humans and machines result in pain, accidents, biomechanical stress, tiredness, and musculoskeletal injuries. Designing for the anthropometrics of end users improves long-term viability. The human body comes in a wide range of sizes and shapes. Manual measurement and 3D scanning procedures, on the other hand, are inefficient and expensive, making precise body measurements difficult. This is especially true for head-worn medical devices. Manual measurement and 3D scanning are inefficient and expensive, making precise body measurements difficult. Grip strength and force were determined using hand measurements. Anthropometric parameter estimate is more precise when a 3D model is used to boost pinnae features. While numerous anatomical features have been gathered to aid in the ergonomic design of wearable devices, there is still a lot more work to be done. In three dimensions, the segment masses and torso Centre of Mass (COM) may be calculated. Researchers tracking mobility would benefit greatly from the ability to locate the body COM using a weighted sum of segment masses. Design features such as comfort and usefulness are crucial. Ergonomic characteristics like taller seats with front slopes and saddle chairs encourage good posture, movement, and alternation. In the creation of wearable technologies, using outdated anthropometric reference standards may be insufficient. This review discuses common issues related to anthropometry in engineering which includes the human body, anthropometric parameters, anthropometric measurements, the force plate method, ergonomic design, and body dimension. The goal is to give a broad overview of the subject.

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Advancements in cognitive ergonomics integration with human-robot collaboration, workload management, and industrial applications

2024 , Ahmad Humaizi Hilmi , Asna Rasyidah Abd Hamid , Wan Abdul Rahman Assyahid Wan Ibrahim

Cognitive ergonomics is increasingly essential in modern industries, particularly in human-robot collaboration (HRC), where it addresses mental workload, decision-making, and overall worker well-being. As industrial systems transition into Industry 4.0 and Industry 5.0, the integration of robotics and artificial intelligence (AI) into human-centered processes necessitates the management of cognitive load. Cognitive ergonomics enhances workplace efficiency by optimizing human-system interactions, reducing mental strain, and improving task performance in complex environments. By focusing on real-time workload management, including the use of biosensors and eye-tracking technologies, industries can monitor cognitive strain, allowing for immediate task adjustments to maintain productivity and safety. Cognitive ergonomics also plays a pivotal role in enhancing human factors in HRC by aligning machine design with human mental capabilities. Effective human-machine interfaces (HMIs) based on cognitive ergonomic principles improve decision-making, reduce errors, and enhance user satisfaction. As industries continue to adopt advanced robotics, the mental demands on workers increase, making cognitive ergonomics crucial for mitigating risks associated with cognitive overload. Future trends point toward the integration of cognitive ergonomics with emerging technologies like AI, wearable devices, and virtual reality (VR), offering new avenues for workload management and decision support. These advancements aim to balance the cognitive demands on workers, ensuring that systems are designed to enhance performance without causing mental fatigue or stress. Overall, cognitive ergonomics remains a vital component in ensuring the well-being and efficiency of workers in technologically advanced industrial environments.

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Explosive Pressing Experiment and Its Challenges to Conduct it on University Level

2020-03-20 , Ahmad Humaizi Hilmi , Yusuf M.A.

Typical press force for hydraulic press machine for most universities are around 10 to 30 ton. For higher load, student uses Ultimate Testing Machine (UTM). Typical press force for UTM for higher learning institution is 300 ton. To obtain more press force, the specimen must be small. This is according to force equation where the smaller the surface area, the higher the force generated on it. However, the problem with small specimen is that it is difficult for researchers to do further investigations for hardness test, tensile test and microstructural analysis. Besides, there is a limit to maximum force a UTM machine can give. This paper presents steps for doing experiments using explosive pressing at university level. The explosive pressing apparatus was an improved designed by the same author. This experiment uses an amount of explosive that is place at top of the apparatus. The experiment is done underground for safety purposes. Explosive handling was done with help from authorized explosive expert. Major benefits of explosive pressing are larger samples can be pressed and the press force is very high. This paper will discuss the steps to do experiment and the challenges while doing explosive pressing using this apparatus. This paper will also show that higher pressing force can lead to finer microstructure of material being pressed.

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Finite element analysis on structural behaviour of geopolymer reinforced concrete beam using Johnson-Cook Damage in ABAQUS

2022 , Nurul Aida Mohd Mortar , Mohd. Mustafa Al Bakri Abdullah , Rafiza Abdul Razak , Kamarudin Hussin , Sanusi Hamat , Ahmad Humaizi Hilmi , Noorfifi Natasha Shahedan , Long Yuan Li , Ikmal Hakem A. Aziz

This paper details a finite element analysis of the behaviour of Si-Al geopolymer concrete beam reinforced steel bar under an impulsive load and hyper velocity speed up to 1 km/s created by an air blast explosion. The initial torsion stiffness and ultimate torsion strength of the beam increased with increasing compressive strength and decreasing stirrup ratio. The study involves building a finite element model to detail the stress distribution and compute the level of damage, displacement, and cracks development on the geopolymer concrete reinforcement beam. This was done in ABAQUS, where a computational model of the finite element was used to determine the elasticity, plasticity, concrete tension damages, concrete damage plasticity, and the viability of the Johnson-Cook Damage method on the Si-Al geopolymer concrete. The results from the numerical simulation show that an increase in the load magnitude at the midspan of the beam leads to a percentage increase in the ultimate damage of the reinforced geopolymer beams failing in shear plastic deformation. The correlation between the numerical and experimental blasting results confirmed that the damage pattern accurately predicts the response of the steel reinforcement Si-Al geopolymer concrete beams, concluded that decreasing the scaled distance from 0.298 kg/m3 to 0.149 kg/m3 increased the deformation percentage.

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Current issues related to biomechanics in engineering

2022 , Ahmad Humaizi Hilmi , Asna Rasyidah Abdul Hamid

Motion capture was employed by Eadweard Muybridge and Etienne-Jules Marey. Industry standard for computing joint kinematics is motion capture. Kinematic analysis is a technique used in biomechanics and mechanical engineering to quantify stiff body motion. A joint moment can be computed in one of two ways: bottom-up or top-down. Joint moments measure muscle and joint tension indirectly. Researchers predicted joint moments using kinematic-based characteristics and machine learning outside of the biomechanics lab.Ankle osteoarthritis causes significant biomechanical issues in the foot and lower leg. Patients' 3D multi-segment kinematic foot models were studied. The technique used is Openpose, which recognises the human body from a single photograph.Falling fear is linked to decreased activity, despondency, and anxiety in the elderly. They adopt a hip approach to manage their GRFs and balance. The lateral ankle technique corrects minor foot placement problems by swiftly moving the pressure point. Angular momentum is affected by foot placement and ground reaction forces. Changing the body's centre of mass along a curved trajectory implies large changes in both ground reaction force impulses and ground reaction force.Lens stiffness and a ciliary muscle anterior/inward displacement produce presbyopia. By 55, the majority of folks have lost their ability to accommodate. Cataracts become common around this time, reaching over 70% by 75. The circumferential and meridional stiffnesses rose with anisotropy from pole to equator, but dropped with distance. The Holzapfel model accurately fits the data from inflation and uniaxial mechanical tests.Anatomical motions of the femur during knee flexion were examined. The data revealed morphological and physiological knee kinematic characteristics. The data led to several hypotheses about axial femoral condyle rotation. This review discusses lower limbs, foot positioning, lens capsule, femoral condyle, muscle activation, collagen fibre, knee joint, and walking speed. The purpose is to provide a general overview on the subject matter.

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Beyond comfort ergonomics in engineering education and design

2023 , Ahmad Humaizi Hilmi , Asna Rasyidah Abdul Hamid

In "Beyond Comfort: Ergonomics in Engineering Education and Design," this review looks at how ergonomic points help make health care places better. It checks how training programs can help reduce hard physical work troubles and stop bone and muscle problems. In terms of teaching, the paper looks at how ergonomic ideas are added into courses, focusing on new teaching ways for better worker performance. It also talks about differences in new learning places, like learning through computer-made realities, and old-style classrooms in engineering teaching. The paper points out many ergonomic problems professionals face in different areas like health care during big health crises, building places, farm work, and fixing railway systems. There are also talks of new tools and changes, like better wheelbarrows and different hospital beds, to make things easy and safe for users. The main idea of the book is to talk about the design and change of tools, work systems, and teaching plans to make ergonomics strong, reduce health problems, and make work output better.

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Human-centered ergonomic: advancements, challenges, and future directions in industrial and occupational settings

2024 , Ahmad Humaizi Hilmi , Asna Rasyidah Abdul Hamid , Wan Abdul Rahman Assyahid Wan Ibrahim

The field of human-centered ergonomics has evolved significantly, especially in industrial and occupational settings, where the focus is on optimizing worker performance and well-being through the integration of advanced technologies. This review paper explores the key advancements, challenges, and future directions in ergonomics as they relate to Industry 4.0, cognitive ergonomics, aging workforces, and sustainable manufacturing. With the rise of Industry 4.0, technologies such as motion capture, virtual reality, and autonomous systems have proven to be invaluable tools in addressing ergonomic risks while improving productivity. These innovations enable better task design and human-machine interactions, reducing both physical strain and cognitive load. However, the integration of technology also presents challenges, particularly for the aging workforce, which is more susceptible to ergonomic stressors. Ergonomic interventions such as assistive devices, like exoskeletons, and tailored workspace designs are critical for maintaining productivity and health among older workers. Furthermore, the review discusses the role of ergonomics in sustainable manufacturing, highlighting how ergonomic principles contribute to environmental goals by reducing energy consumption, waste, and physical strain. Cognitive ergonomics, which addresses mental workload and human-computer interaction, is another crucial area explored in this paper. As automation increases, optimizing human cognitive performance is essential to reducing errors and enhancing safety in complex work environments. In conclusion, while advancements in technology offer promising solutions to many ergonomic challenges, the future of human-centered ergonomics will require continued research and innovation to address the evolving needs of workers in diverse and technologically advanced environments. The ongoing development of ergonomic interventions that balance human well-being with industrial efficiency will remain central to the future of work.

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Simulation Study on Hypervelocity Penetration of Lab Scaled Shape Charge Mechanism

2022-01-01 , Kamarudin K.H. , Zaidi A.M.A. , Ahmad Humaizi Hilmi , Abdullah M.F. , Nor N.M. , Ismail A. , Yusof M.A. , Rasool Mohideen S.

Shaped charge (SC) is a mechanism used by defence industries as anti-armored weapon to penetrate armored plates. Numerous studies have been conducted on the shaped charged effects. However, experimental studies are limited due to great safety requirement and limited access to high grade explosive. Due to these limitations, an experimental study on a small-scale shaped charge mechanism (SCM) penetration blast test was conducted against five (5) types of target materials. The experimental data is then verified by simulation to proof that it can be used to predict the SC penetration data. This paper intent to present a comparative study on the effect of shaped charge blast conducted by simulation with the actual experimental results. In order to conduct this study, a 2D AUTODYN software were used to develop the SC blast model against five (5) types of target materials. This study concludes that the 2D AUTODYN simulations results can predict the hypervelocity penetration for all target materials compared to the experimental test with an average difference of 9.1 %.

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Musculoskeletal disorders industrial insights and ergonomic interventions

2023 , Ahmad Humaizi Hilmi , Asna Rasyidah Abdul Hamid

In response to the rising incidence of musculoskeletal disorders (MSDs) across diverse work environments, extensive research has been undertaken. Within the apparel sector, initiatives have included workstation redesigns to alleviate worker strain. Emphasis has also been placed on formulating explicit ergonomic risk assessment standards, particularly for roles associated with heavy machinery, exemplified by container terminal operators. The agricultural domain, particularly manual farming activities in Haryana, India, has been studied to comprehend the distinct challenges encountered. The ergonomic implications for fish processing laborers, subjected to cold, damp conditions and repetitive tasks, have also been examined. Notably, the integration of biomechanics instrumentation in occupational health offers insights into refining human work-related movements for improved health. Scrutiny has been extended to varied workplaces, like flour production units and oil and gas enterprises, to discern MSD origins and propose corrective measures. With technological advancements, ergonomics now employs sophisticated tools such as computerized dynamometers for precise risk evaluations. Detailed biomechanics assessments further elucidate the physical demands on workers. Other industries, including textiles, have seen ergonomic appraisals aiming to diminish manual task strains, while the laborintensive dairy farming sector has also been evaluated. Cumulatively, these comprehensive research endeavors pave the way for a more informed approach, suggesting preventive and mitigative strategies against MSDs across sectors.

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A method to press powder at 6000 ton using small amount of explosive

2017-12-04 , Ahmad Humaizi Hilmi , Nor Azmaliana Azmi , Ariffin Ismail

Large die hydraulic press forces are one of the key instruments in making jumbo planes. The machine can produce aircraft components such as wing spars, landing gear supports and armor plates. Superpower nations such as USA, Russia, Germany, Japan, Korea and China have large die hydraulic press which can press 50,000 tons. In Malaysia, heavy-duty press is available from companies such as Proton that builds chassis for cars. However, that heavy-duty press is not able to produce better bulkhead for engines, fuselage, and wings of an aircraft. This paper presents the design of an apparatus that uses 50 grams of commercial grade explosives to produce 6000 tons of compaction. This is a first step towards producing larger scale apparatus that can produce 50,000-ton press. The design was done using AUTODYN blast simulation software. According to the results, the maximum load the apparatus can withstand was 6000 tons which was contributed by 50 grams of commercial explosive(Emulex). Explosive size larger than 50 grams will lead to catastrophic failure. Fabrication of the apparatus was completed. However, testing of the apparatus is not presented in this article.

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