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941.
目前行驶在长江三角洲限制性航道上的船型与GB 50139—2004《内河通航标准》所列的设计船型尺度有一定的差别,交通运输部规划的集装箱船型在GB 50139—2004《内河通航标准》中没有列入,限制性航道尺度确定只有规范最小取值没有计算公式,但在实际应用过程中,航道尺度与船型尺度是直接相关的.结合相关航道设计经验,探讨如何根据设计船型尺度合理确定限制性航道设计尺度的方法. 相似文献
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There have not been many studies on the factors that affect chest deflection, although the US NCAP thoracic injury criterion was recently shifted from the 3-msec clip to chest deflection. This study explored these factors and proposed a design methodology for the factors to minimize chest deflection. Because injuries can become severe if the driver crashes against the vehicle interior, this study also sought a solution using a penalty function to prevent crashes with the interior and minimize injuries. First, a MADYMO model was made to simulate US NCAP and EURO NCAP tests by one-to-one and stochastic verifications. Second, a sensitivity analysis was conducted to find the major factors that affect chest deflection. Lastly, the factors identified via the sensitivity analysis were optimized to propose design guidelines that helped vehicles receive high star ratings in US NCAP and EURO NCAP tests and helped minimize the possibility of hard contact between the driver and the vehicle interior by utilizing a penalty function and the Taguchi method. 相似文献
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In this study, a control strategy for a dual mode power split-type hybrid electric vehicle (HEV) is developed based on the powertrain efficiency. To evaluate the transmission characteristics of the dual mode power split transmission (PST), a mechanical loss model of the transmission (TM loss) is constructed. The transmission efficiency, including the TM loss, is evaluated for the dual mode PST. Two control strategies for the dual mode PST are proposed. An optimal operation line (OOL) control strategy is developed to maintain a high engine thermal efficiency by controlling the engine operation point on the OOL. A speed ratio (SR) control strategy is proposed to obtain a greater transmission efficiency by shifting the engine operation point when the dual mode PST operates near the mechanical points. Using the TM loss and the proposed control strategies, a vehicle performance simulation is conducted to evaluate the performance of the two control strategies for dual mode PST. The simulation results demonstrate that, for the SR control strategy, the engine efficiency decreases because the engine operates beyond the OOL. However, the transmission efficiency of the dual mode PST increases because the PST operates near the mechanical point where the PST shows the greatest transmission efficiency. Consequently, the fuel economy of the SR control strategy is improved by 3.8% compared with the OOL control strategy. 相似文献
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D. O. Kang S. J. Heo M. S. Kim W. C. Choi I. H. Kim 《International Journal of Automotive Technology》2012,13(1):109-122
This study presents the robust design optimization process of suspension system for improving vehicle dynamic performance
(ride comfort, handling stability). The proposed design method is so called target cascading method where the design target
of the system is cascaded from a vehicle level to a suspension system level. To formalize the proposed method in the view
of design process, the design problem structure of suspension system is defined as a (hierarchical) multilevel design optimization,
and the design problem for each level is solved using the robust design optimization technique based on a meta-model. Then,
In order to verify the proposed design concept, it designed suspension system. For the vehicle level, 44 random variables
with 3% of coefficient of variance (COV) were selected and the proposed design process solved the problem by using only 88
exact analyses that included 49 analyses for the initial meta-model and 39 analyses for SAO. For the suspension level, 54
random variables with 10% of COV were selected and the optimal designs solved the problem by using only 168 exact analyses
for the front suspension system. Furthermore, 73 random variables with 10% of COV were selected and optimal designs solved
the problem by using only 252 exact analyses for the rear suspension system. In order to compare the vehicle dynamic performance
between the optimal design model and the initial design model, the ride comfort and the handling stability was analyzed and
found to be improved by 16% and by 37%, respectively. This result proves that the suggested design method of suspension system
is effective and systematic. 相似文献
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