Current Issue : January - March Volume : 2015 Issue Number : 1 Articles : 5 Articles
Significant changes in vehicle loads have occurred in China due to the development of the automobile industry and transportation\nwithin the past two decades, particularly the rapid increase in traffic flow and the large-scale emergence of heavy trucks. However,\nresearch into vehicle loadings on urban bridges is not well developed. In this study, based on traffic flow data collected using a\nweigh-in-motion system installed on an expressway in an urban logistics zone, we analyzed the traffic flow, vehicle types, and gross\nvehicle weight (GVW) features and developed models for the vehicle load and fatigue load. According to the axle space, axle types,\nand axle number, the trucks in the traffic flow were classified into 10 representative vehicle types. The probability distribution of the\nGVW was fitted to a three-class mixed log-normal distribution. Using the improved Gumbel method, we determined the extreme\nvalue distribution of the vehicle loadings in the purpose reference period and assessed the vehicle loadings of urban bridges. In\naddition, using the equivalent damage theory, six equivalent vehicle models were established according to the measurements of the\naxle weight and axle space, thereby obtaining a simplified model of fatigue vehicle loadings on urban expressway bridges....
There are many process parameters which have great effect on the forming quality of parts during automobile panel stamping\nforming process. This paper took automotive lower floor board as the research object; the forming process was analyzed by finite\nelement simulation usingDynaform.The influences of four main process parameters including BHF(blank holder force), die corner\nradius, friction coefficient, and die clearance on the maximum thinning rate and the maximum thickening rate were researched\nbased on orthogonal experiment. The results show that the influences of each value of various factors on the target are not identical.\nOn this basis, the optimization of the four parameters was carried out, and the high quality product was obtained and the maximum\nthinning rate and maximum thickening rate were effectively controlled. The results also show that the simulation analysis provides\nthe basis for the optimization of the forming process parameters, and it can greatly shorten the die manufacturing cycles, reduce\nthe production costs, and improve the production efficiency...
A ball joint for an automobile steering system is a pivot component which is connected to knuckle and lower control arm. The\nmanufacturing process for its caulking comprises spinning and deforming. In this study, the process was simulated by flexible\nmultibody dynamics. The caulking was evaluated qualitatively through numerical analysis and inspecting a plastically deformed\nshape.The structural responses of a ball joint, namely, pull-out strength and stiffness, are commonly investigated in the development\nprocess.Thus, following the caulking analysis, the structural responses were considered. In addition, three design variables related\nto the manufacturing process were defined, and the effects of design variables with respect to pull-out strength, caulking depth, and\nmaximum stress were obtained by introducing the DOE using an L9 orthogonal array. Finally, the optimum design maximizing the\npull-out strength was suggested. For the final design, the caulking quality and the pull-out strength were investigated by making\nsix samples and their tests....
Greenhouse gas emitted by the transport sector around the world is a serious issue of concern. To minimize such emission the\nautomobile engineers have been working relentlessly. Researchers have been trying hard to switch fossil fuel to alternative fuels and\nattempting to various driving strategies to make traffic flow smooth and to reduce traffic congestion and emission of greenhouse\ngas. Automobile emits a massive amount of pollutants such as CarbonMonoxide (CO), hydrocarbons (HC), carbon dioxide (CO2),\nparticulate matter (PM), and oxides of nitrogen (NO????). Intelligent transport system (ITS) technologies can be implemented to\nlower pollutant emissions and reduction of fuel consumption. This paper investigates the ITS techniques and technologies for\nthe reduction of fuel consumption and minimization of the exhaust pollutant. It highlights the environmental impact of the ITS\napplication to provide the state-of-art green solution. A case study also advocates that ITS technology reduces fuel consumption\nand exhaust pollutant in the urban environment...
The goal of our paper is to complete some results presented by Craioveanu et al. (1998) concerning the nonlinear stability of the\nequilibrium states of the car with two trailers� dynamics. In addition, the Lax formulation, numerical integration via Lie-Trotter,\nand Kahan�s integrator for these dynamics are presented....
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