Applied Mechanics and Materials Vol. 165

Abstract: This paper presents the design and development of the UTeM Perodua Eco-Challenge vehicle. The aim of the project was to develop a new generation of fuel efficient car which able to travel the longest distance using 0.5 liter of RON95 fuel. The eco-car was designed as a single seat rear wheel drive vehicle powered by a 660cc fuel injection engine with manual 5-speed transmission and weighs of 355 kg with 30:70 load distribution. The key design features of the fuel efficient car were also discussed in this paper such as space frame chassis design, braking system, composite bodywork and suspension system. Modifications on the engine were also discussed such as engine management to further increase the vehicle fuel efficiency.

Abstract: In this study an aluminium alloy is introduced as an alternative lightweight material in automotive industry. In order to achieve lightweight design, the study was undertaken on a side member of automotive parts. Crashworthiness performance of AA5182 side member is compared to the automotive steel side member. By designing 16 experiments based on full factorial design, the effect of thickness with four levels on the crash performance of the AA5182 side member was investigated for each loading conditions, axial and oblique loading. Mass, energy absorbed and maximum force is set as the evaluation criterion and the full factorial design has presented several designs to serve the evaluated criterion.

Abstract: A mathematical modelling approach of a multi-body wheel suspension is presented. The wheel suspension is modelled in a modular manner so that different types of vehicles can be simulated. The inter-changeability of the wheel suspensions is achieved by calculating the translational and rotational Jacobian matrix and its partial time derivatives for the wheel carrier and the wheel. The results of modelling the kinematics of a McPherson wheel suspension are shown.

Abstract: This paper discusses the fatigue fracture behaviour of aluminium alloy AA6061-T6 under spectrum loadings at room and elevated temperatures. The load sequence can have a very significant effect in fatigue lives and normally the fatigue strength of material decrease with increasing temperature. In this study, variable amplitude loading (VAL) signal was obtained from the engine mount bracket of an automobile in a normal driving condition. Constant amplitude loading (CAL), high to low and low to high spectrum loadings were then derived from the VAL obtained from the data capturing process to study the fatigue behaviour that subjected to spectrum loadings at the room and elevated temperatures. The fatigue tests were performed according to an ASTM E466 standard using a servo-hydraulic fatigue testing machine. Fatigue fracture surfaces were then sectioned and inspected by employing a high magnification microscope. Results indicated that fracture surface behaviours of specimens were influenced significantly by the load sequence and temperatures, which can be related to the fatigue lives of aluminium alloy under spectrum loadings.

Abstract: As a government agency focusing on road safety research, MIROS has regularly involved in policy-making exercises which blend together the great understanding of technical, legislative and social framework. This paper recapped the development of a conceptual model of the Malaysian automotive ecosystem with special reference to car maintenance issues, particularly with regard to one of the NAP measures Gradual phase out of imported used parts and components. The methodology of the study was designed into two focus group discussions (FGD) and extensive literature reviews. Internal FGDs were conducted as the study precursor and external discussions involved other ministries and agencies reps. Extensive literature reviews include journals, proceedings, unpublished reports, as well as web-based sources. A conceptual model of the domestic automotive ecosystem is proposed in this paper together with the discussion on NAP measures and relevant future research within the models framework.

Abstract: Having relevant features for representing dataset would motivate such algorithms to provide a highly accurate classification system in less-consuming time. Unfortunately, one good set of features is sometimes not fit to all learning algorithms. To confirm that learning algorithm selection does not weights system accuracy user has to validate that the given dataset is a feature-oriented dataset. Thus, in this study we propose a simple verification procedure based on multi objective approach by means of elitist Non-dominated Sorting in Genetic Algorithm (NSGA-II). The way NSGA-II performs in this work is quite similar to the feature selection procedure except on interpretation of the results i.e. set of optimal solutions. Two conflicting minimization elements namely classification error and number of used features are taken as objective functions. A case study of fatigue segment classification was chosen for the purpose of this study where simulations were repeated using four single classifiers such as Naive-Bayes, k nearest neighbours, decision tree and radial basis function. The proposed procedure demonstrates that only two features are needed for classifying a fatigue segment task without having to place concern on learning algorithm

Abstract: Thin-walled metallic tubular structures are generally used as impact energy absorber in automotive structures due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, unlike a normal passenger car where the impact energy can be distributed throughout the whole structure, the impact energy absorbing system of an Eco-Challenge car is confined within a limited space on the front bulkhead. The challenge is to develop an impact attenuator system that can effectively absorb the impact energy within the given space and fulfil the specified rate of deceleration. This new design utilized the standard Aluminium 6063 circular tubes, cut and welded into specific configurations i.e. stacked toroidal tubes with central axial tube sandwiched between two flat plates. Two configurations were investigated; circular and square toroids. Explicit non-linear FEA software was used to determine the impact response i.e. energy absorption, impact force and rate of deceleration. Both configurations showed promising results but the configuration that can be readily fabricated was chosen as the final design.

Abstract: This paper presents an assessment for the airborne sound insulation provided by double glazed panels. The glazed panels were glass, acrylic and polycarbonate with a thickness of 4 mm. The panels were tested for 10 mm, 20 mm and 30 mm air gap thicknesses. The experiments were conducted in a transmission loss facility consisting of semi anechoic and reverberation chambers complying with International Standards ISO 140-1 and ISO 140-3. The panels were subjected to airborne sound. Glass, acrylic and polycarbonate panel absorb noise most effectively above 500 Hz with the absorption peaks at 1000 Hz. The single number sound reduction index (R_W) for glass, acrylic and polycarbonate as double layers with air gap were evaluated. The results showed that the glass has higher R_W for all air gaps and the results were 40.5 dB, 37.7 dB and 37.4 dB, respectively. This could be attributed mainly to the material density which is higher for the glass.

Abstract: This paper presents impact behaviour and energy absorption response of car door safety beams. Low carbon steel of thickness 2.25 mm, designed into four different shapes of, tube-beam, I-beam and II-beam were used in this experiment to study the effect of impact load on the crash characteristic of the door beams in terms of load bearing and attenuation of energy. The tube-beam is the conventional beam commonly used in cars today. The reason propelling the investigation of other beams is to draw a parallel comparison with the conventional tube beam and possibly obtain an optimised design in terms of impact absorption capability. Masses of impactors used in the impact load simulations were 10 kg, 20 kg, 30 kg, 40 kg and 50 kg at an impact speed of 30 km/h. Analysis were carried out on all samples focusing on energy absorption and deformation characteristics of the beam structures using Pam Crash^TM finite element analysis software. Results from this studies indicated that the II-beam design is better than the other beams in terms of the energy absorption and deformation. The proposed II-beam design may be able to prolong the useful life of passenger car door.

Abstract: Driving simulators (DS) are extensively used worldwide as tools in research and training related to driving behaviour and road safety. However, DS have yet to be used extensively in Malaysia. While there is no guarantee that the use of DS may have direct positive impact on road safety, it offers an objective and insightful opportunity to measure and understand driving behaviour. This is especially relevant in Malaysia as it struggles to reduce the high number of fatalities due to road crashes. This paper reviews the role of simulators in research and training worldwide to better understand the driving behaviour and how Malaysia can benefit from useful tool.