Current Issue : January - March Volume : 2018 Issue Number : 1 Articles : 5 Articles
This study develops an automobile life-cycle analysis framework considering lifetimes\nof new and used passenger cars. Using the analysis framework based on the Weibull\nsurvival distributions of new and used cars, I addressed the question of how the market\nexpansion and lifetime extension of used cars affect life-cycle CO2 emissions through\nthe entire economy. The results show the following.Under the benchmark lifetime\nfunction, a 10% increase in the market share of used cars under benchmark average\nnew vehicle lifetime of 11.50 years yields 16.9 million tons of CO2 reduction in the\ncumulated life-cycle CO2 emissions during 1993ââ?¬â??2014. I further found that a combined\npolicy of vehicle lifetime extension and market expansion of ââ?¬Å?usedââ?¬Â cars can contribute\ntoward a low-carbon transition society. I conclude that modifying the demand policy\nwith a focus on ââ?¬Å?usedââ?¬Â cars with higher fuel efficiency, as well as setting a target car age\nof used cars, would be environmentally beneficial....
Conventional eddy current braking is limited in effectiveness to only the high vehicular speed\nregion. As the vehicle slows, the conventional eddy current brake loses effectiveness. This\ninherent drawback is due to the use of static/stationary magnetic field in the brake system. This\nstudy presents a solution - the use of rotating magnetic field in the brake system. By the study\ndesign, the conducting brake disc rotates between the poles of an electromagnet. A constant airgap\nseparates the disc from the poles on either side. The electromagnet windings (each with a\ncore) are made poly-phase so that when an equivalent poly-phase source supplies ac to the\nelectromagnet windings, a rotating magnetic field is obtained. The rotating magnetic field comes on\nwhen the brake is applied and eddy current is induced in the conducting brake disc to effectuate\nretardation. The brake disc is coupled to the road wheel so that retardation of the brake disc\ntransmits directly to the road wheel. The eddy current braking torque is a measure of the braking\npower. The braking torque varies directly as the relative speed between the conducting brake disc and the eddy current brake magnetic field. The braking torque is studied under three main\nconditions. These are when the brake disc and the magnetic field rotate in opposite directions,\nwhen the brake disc and the magnetic field rotate in the same direction and when the wheel is\nstationary with only the magnetic field rotating. Braking performance is studied in terms of stopping\na vehicle, slowing and preventing motion. Results show that stopping and slowing are achieved\nwhen the magnetic field rotates opposite the direction of the brake disc rotation. For stationary\nwheel, motion will not occur as long as the torque which tends to be tractive is counterbalanced by\nfriction at the wheels and the vehicular mass inertia. Modeling and simulation in this study are done\nusing Mat Lab ââ?¬â?? Simulink software....
A half-car vibration model of an electric vehicle driven by rear in-wheel motors was developed using bond graph theory and the\nmodular modeling method. Based on the bond graph model, modal analysis was carried out to study the vibration characteristics\nof the electric vehicle. To verify the effectiveness of the established model, the results were compared to ones computed on the\nground of modal analysis and Newton equations. The comparison shows that the vibration model of the electric vehicle based on\nbond graph theory not only is able to better compute the natural frequency but also can easily determine the deformation mode,\nmomentummode, and other isomorphism modes and describe the dynamic characteristics of an electric vehicle driven by in-wheel\nmotors more comprehensively than other modal analysis methods....
The ability to predict the weathering performance of the clearcoat system over\na short period of time is essential for the design and development of coating\nproduction. Thus, the primary objective of the present study is to investigate\nwhether it is possible to predict the weathering performance of an automotive\npaint system through determination of surface roughness, R\na, and microhardness\nbefore and after various weathering exposure times (0, 24, 168, 336,\n504, 672 hours) and when employing two different detergent materials\n(house-use detergent and car wash detergent). The data were analysed using a\npair-sample t -Test, with 0.05 level of significance. It was found that the total\nnet of degradation in the clearcoat level during the first 24 hours was R\na ââ?°Ë? 30.3\nnm (for surface roughness) and 1.358 HV (for the Ã?¼-hardness) when using the\nhouse-use detergent. In contrast, it was found to be R\na ââ?°Ë? 4.6 nm (for surface\nroughness) and 1.133 HV (for Ã?¼-hardness) when using the car wash detergent.\nAlso, increased time of weathering (up to 672 hours) increases the R\na and\nÃ?¼-hardness values. It can therefore be concluded that the effect of house-use\ndetergent was more severe than that of car wash detergent on the clearcoat\nsystem....
This paper presents a double loop controller for a 7-DoF automobile electrohydraulic active suspension via T-S fuzzy modelling\ntechnique. The outer loop controller employs a modified ...
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