Current Issue : July - September Volume : 2019 Issue Number : 3 Articles : 5 Articles
Carbon emissions, produced by automobile fuel consumption, are termed as the key reason\nleading to global warming. The highway circular curve constitutes a major factor impacting vehicle\ncarbon emissions. It is deemed quite essential to investigate the association existing between circular\ncurve and carbon emissions. On the basis of the IPCC carbon emission conversion methodology, the\ncurrent research work put forward a carbon emission conversion methodology suitable for Chinaâ??s\ndiesel status. There are 99 groupsâ?? test data of diesel trucks during the trip, which were attained on\n23 circular curves in northwestern China. The test road type was key arterial roads having a design\nspeed greater than or equal to 60 km/h, besides having no roundabouts and crossings. Carbon\nemission data were generated with the use of carbon emission conversion methodologies and fuel\nconsumption data from field tests. As the results suggested, carbon emissions decline with the\nincrease in the radius of circular curve. A carbon emission quantitative model was established with\nthe radius and length of circular curve, coupled with the initial velocity as the key impacting factors.\nIn comparison with carbon emissions under circular curve section and flat section scenarios, the\nminimum curve radius impacting carbon emissions is 500 m. This research work provided herein a\ntool for the quantification of carbon emissions and a reference for a low-carbon highway design....
Hot-stamped ultra-high strength steels have been widely used in automobile structural\nparts. Considering the high splash tendency in resistance spot welding due to their extremely high\nhardness, in this work, microstructural characteristics and mechanical performance of the resistance\nspot welded ultra-high strength steels are investigated. The results indicate that the interface between\nthe nugget and heat-affected zone (HAZ) is the weakest zone where fractures initiate. In tensile\nshearing tests, a qualified spot welding joint failed with a button-shaped fracture. Welding defects\nwould significantly decrease the load-carrying capacity and lead to interfacial fracture, except for\na button-shaped fracture. In spot welding, it was found that a specific mid-frequency alternating\ncurrent (AC) input mode, in which a 6 ms cooling cycle was inserted between every two neighboring\ncurrent pulses, can avoid the splash in the spot welding of hot-stamped hardened steels....
Industry 4.0 promotes the development of traditional manufacturing industry to digitization, networking, and intellectualization.\nSmart factory is composed of network that includes production equipment, robot, conveyor, and logistics system. According to the\ncharacteristics of the mixed flow assembly, a simulation platform of automobile mixed flow assembly is built based on industry 4.0\nin the paper, which operates and manages automobile assembly, logistics warehouse, and CPS effectively. On this basis, FlexSim\nsoftware is adopted to establish the auto-mixed assembly model that finds out the bottleneck of auto-mixed assembly problem. By\nmeans of parameter adjustment, rearrangement, and merger of process, the whole assembly time of the 500 automobiles dropped\nby 33 hours, the equipment utilization rate increased by 20.19%, and the average blocked rate decreased by 21.19%.The optimized\nresults show that the proposed model can greatly increase manufacturing efficiency and practical application in industry 4.0....
In this article, a novel electromagnetic-frictional integrated brake is proposed, and its\nstructure and working principle are introduced. The geometric model and mathematical models of\nintegrated brake were established, and the multi-field coupling mechanism of integrated brake were\nanalyzed. With BYD Qin as a reference vehicle, the boundary conditions of thermal load and force\nload of integrated brake were determined according to its structure and performance parameters.\nBased on the COMSOL software, numerical coupling calculations of electric, magnetic, thermal, and\nsolid fields of integrated brake were carried out respectively in the emergency and downhill braking\nat a constant speed. The axial, circumferential, and radial temperature distributions of integrated\nbrake disc were analyzed respectively, and they were compared with those of the traditional friction\nbrake disc. The analysis results show that the proposed integrated brake can effectively improve the\nheat fading resistance of automotive brake during emergency and continuous braking. Under the two\nbraking conditions, the temperature rise of friction brake was faster than that of an electromagnetic\nbrake, and the effect of the electromagnetic brake on temperature rise of integrated brake was small....
Increasing shares of renewable electricity generation lead to fundamental changes of the\nelectricity supply, resulting in varying supply mixes and environmental impacts. The hourly-defined\nlife cycle assessment (HD-LCA) approach aims to capture the environmental profile of electricity\nsupply in an hourly resolution. It offers a flexible connectivity to unit commitment models or\nreal-time electricity production and consumption data from electricity suppliers. When charging EVs,\nthe environmental impact of the charging session depends on the electricity mix during the session.\nThis paper introduces the combination of HD-LCA and smart charging and illustrates its impacts on\nthe life cycle greenhouse gas emissions of BEVs....
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