Effect of strain rate on indentation behaviour of kenaf-based fibre metal laminates

Kenaf natural fibre has become the subject of interest for a wide range of engineering sectors due to its biodegradable and robust mechanical properties [1, 2]. Akil et. al. [3] presented a review on kenaf fibre reinforced composites and mentioned that the application of kenaf fibre-reinforced composite as an alternative composite material is highly plausible with both lightweight and low cost as its main advantages. This situation has lead researchers to investigate the potential offered by kenaf fibre reinforced composites [4-6]. However, research on kenaf-based fibre metal laminates (FMLs) is still not clear and thus demands extensive research investigation. In this study, the effect of strain rate on the indentation behaviour of the FMLs subjected to static indentation loading was investigated. The fibre metal laminates were made of chopped strand mat kenaf fibre with epoxy resin composite and 0.6 mm thickness of 1100-O aluminium alloy sheet by using vacuum infusion process (VIP) and hydraulic pressing technique. Several samples of 2/1 lay-up and 3/2 lay-up of FMLs were prepared for indentation tests. The experiments were conducted by using a universal testing machine with strain rate of 1 mm/min, 10 mm/min and 100 mm/min

Dynamic analysis of friction stir welding joints in dissimilar material plate structure

Friction stir welding (FSW) is a welding process that widely used as a solid state joining process for producing welded structure of similar and dissimilar materials such as aluminum alloy, magnesium etc. FSW process has expanded rapidly in industries including aerospace, automotive and maritime due to several advantages compared to other fusion welding. In this paper, experimental modal analysis (EMA) and normal mode finite element analysis (FEA) of the FSW welded joint structure of materials AA6061 and AA7075 will be carried out to identify dynamic properties. Rigid Body Element (RBE2) in MSC NASTRAN/PATRAN is used to model the welds and their compatibility for representing FSW welded structure also being identified. Model updating is performed to minimize the discrepancy between EMA and FEA. Model updating will be acted as an optimization method and is being presented using the structural optimization capability. Finite model updating could be done in individual components and welded structure. RBE2 connecting element can be used to represent friction stir welding with good accuracy

ASSESSMENT OF AUTONOMOUS EMERGENCY BRAKING (AEB) PEDESTRIAN SYSTEM IMPACT ON 2016 – 2020 MALAYSIAN ANIMAL-CROSSINGS ACCIDENTS DATA

The trend of animal-vehicle collision (AVCs) occurrences over the past years demonstrates increasing numbers, and this call for a proper mitigation plan by appropriate authority bodies. Autonomous Emergency Braking (AEB) pedestrian system - proven effective in collision prevention and mitigation for vehicle-pedestrian collision – can potentially expand its original functionality to AVCs avoidance. This study presents a new data assessment method to predict the impact of AEB pedestrian system implementation on vehicles to reduce AVCs cases from 2016 to 2020. In general, a new scoring system is introduced whereby fitment rating points of 1, 0.5 and 0 are given to describe successful crash avoidance, crash mitigation with reduced damage and failed crash avoidance. Several noteworthy findings were discovered in assessing impact data from five significant AEB-AVCs. The effectiveness of AEB is found to be correlated with camera detection, system working speed range, frequent collision time, human casualties, and heavy vehicles. In general, the results indicate overall positive consequences of AEB implementation to reduce AVCs, providing concrete reasoning for standardising AEB pedestrian systems in all manufactured road-legal vehicles for upcoming years

Auditory alert for in-vehicle safety technologies: a review

Safety technology has evolved rapidly in the past few years to become much more driver-aware and automatic. Many of these technologies build upon one another in a good, better, best pattern to provide the safest possible driving experience. It is expected that this system can eliminate or mitigate road accidents due to reckless and careless driving. However, safety or driver-assistance features are no substitute for the driver's responsibility to operate safely. A survey revealed that the warning alarms were turned off by 70% of drivers due to annoying audio characteristics. It is vital to consider frustration linked to an alarm, where it can affect the driver's behavior. It is recommended to identify optimum chime sound characteristics for the driver’s alert and respond appropriately to improve the effectiveness of the auditory signal. In this paper, a review on the identification of the type of warning modality, frequency setting, and warning priority for vehicle safety features technology from the selected vehicle manufacturers are explained

Rearward visibility assessment and a proposed performance scoring for ASEAN NCAP

Asia has the highest number of registered motorcycles globally and the recent data has shown that motorcycles fatalities has been the major accident and death cases in ASEAN Region. One of the major concerns is the visibility of motorcycles to other vehicles on the road. Thus, in this project, ECE R46 and FMVSS regulations have been referred as the base guidelines to establish a novel test protocols for vehicles rearward visibility assessment. Sixteen cars have been benchmarked and analysed in term of their rear-view mirror (Class I) and external mirror (Class III) performance. Motorcycles visibility to the vehicles’ Class I and Class III mirrors also been assessed by converting the measured data into number of motorcycles based on its width. A proposed performance scoring system for ASEAN NCAP has been developed based on that to address the Motorcycle Safety pillar

A systematic review on the autonomous emergency steering assessments and tests methodology in ASEAN

Safety should be the top priority for any automaker - because traffic accidents roughly killed 1.4 million people worldwide, ranking tenth on the World Health Organization's list of leading causes of death. Two decades ago, the focus was on passive safety, where it helps vehicle occupants to survive the crash. However, the frontier in safety innovation has moved beyond airbags and side-impact protection. Today, the frontier is active safety for preventing collisions before they occur. In Euro NCAP 2025 Roadmap, this active safety frontier falls under the primary safety and has become one of the overall safety rating initiatives toward safer cars. The primary safety features four technologies to be assessed, including driver monitoring (2020), automatic emergency steering (2020, 2022), autonomous emergency braking (2020, 2022), and V2x (2024). However, this initiative is partially encapsulated in the ASEAN NCAP Roadmap 2021-2025 under – 'Safety Assist' technological feature. For instance, in the new roadmap, ASEAN NCAP only focuses on Auto Emergency Braking (AEB) technology. This AEB is a feature to alert drivers to an imminent crash and help them use the car's maximum capacity. Therefore, as benchmarked to the EURO NCAP, this paper comprehensively reviews the AES demand, assessments, control, and testing methodology and can be further developed to consolidate for the ASEAN NCAP safety rating schemes

Establishment of 3D-printed child manikins using anthropometric data of 6- and 10-year-old ASEAN children

The New Car Assessment Programme for Southeast Asian Countries (ASEAN NCAP) has been working hard to increase vehicle safety levels in the ASEAN region. To ensure a significant impact on the ASEAN community, few enhancements need to be made to their test methodology and facilities. As an example, ASEAN NCAP is using child manikins with generic build in their vehicle safety assessment. Meanwhile, vehicle manufacturers and product developers are also using these generic references in their product designs such as the seat restraint system, child seat design, etc. For the improvement of vehicle safety especially for the ASEAN region, dedicated manikins with ASEAN anthropometric measurements are necessary. This paper aims to describe the development of 3D-printed manikins based on anthropometric data of ASEAN children aged 6 and 10 years old. The completed prototypes will be tested using a selected vehicle safety assessment (i.e., Child Restraint System installation) and intended to be applied for design refinement of vehicle safety systems

Finite Element Modelling and Damage Detection of Seam Weld

© Springer Nature Singapore Pte Ltd 2020. Seam welds are widely used in assembled structures for connecting components. However, the dynamic effects of a seam weld are often difficult to characterise in numerical models for several reasons: (1) it is often not wise to build a fine mesh on the seam line which will add considerable computational cost for a structure with many welds, (2) the mechanical properties of weld materials are not well known; (3) sometimes some geometric information about welds is not known beforehand. In this work, the finite element model of a welding connection part is developed by employing CSEAM element in NASTRAN and its feasibility for representing a seam weld is investigated. Based on this result, a damage detection method by updating the properties of the built CSEAM elements is also proposed for welding quality assurance. The damage takes the form of a gap in the weld which causes a sharp change of model strain energy at the edges of the gap for certain vibration modes. Specifically, the model strain energy shape is used as the objective function. A Kriging model is introduced for efficiency and simulation of a T-shaped welded plate structure to demonstrate the effectiveness of this method

Motion sickness mitigation in autonomous vehicle: a mini-review

An autonomous vehicle is a rapidly evolving technology that received attention from researchers due to its potential benefits. Besides the advantages, there are also non-negligible issues that need to be overcome in the middle of the autonomous vehicle development process. Among all the challenges, one of the important topics that have not gained adequate consideration is motion sickness (MS). This paper reviews the benefit and challenges of autonomous vehicles, MS factors, the quantifying methods of MS, and the mitigation strategies of MS. Considering the importance of minimizing MS, it is concluded that the number of strategies to lessen MS's severity is still lacking; hence, requiring more attention from automotive researchers

Detection of damage in welded structure using experimental modal data

A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region)