共查询到20条相似文献,搜索用时 0 毫秒
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针对某一曲线连续钢箱梁桥进行梁单元及板单元的计算,比较计算结果,并分析原因,为相关设计计算提供一些借鉴. 相似文献
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基于拉压等效与弯曲等效方法,提出了钢纤维混凝土与钢结合梁桥面板换算为单一材料等效板单元的计算模式 ,导出了等效板单元的厚度和弹性模量的计算式.可方便地采用一般的有限元程序对结合梁桥进行空间分析. 对一座实际的钢纤维混凝土与钢结合梁桥进行了空间应力分析及静载试验. 相似文献
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考虑空间效应的钢-混凝土组合梁单元研究 总被引:2,自引:0,他引:2
为了计算钢-混凝土组合梁空间受力时的剪力滞效应和扭转翘曲变形,以最小势能原理为基础,根据Vlasov薄壁梁理论并考虑组合梁混凝土翼板宽厚的特点,提出了一种用于组合梁空间分析的梁段单元,并推导了单元刚度矩阵、等效节点荷载列阵,该单元具有2个节点共16个自由度,能考虑拉压、弯曲、扭转、翘曲和剪力滞效应.计算结果表明:相对于普通的有限元分析方法,运用该单元进行结构分析具有计算精度高、计算量小的优点. 相似文献
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天然气/汽油两用燃料汽车点火提前角适应性优化设计 总被引:2,自引:1,他引:2
为了使天然气/汽油两用燃料汽车燃用不同的燃料时,能自动改变点火提前角,从而保证发动机在不同的转速时都在最佳点火提前角下工作,研究了两用燃料汽车点火提前角的优化调整方法,通过试验得到了发动机燃用天然气和汽油时,最佳点火提前角相差的相关角度,研制了一种利用89C2051单片机定时器/计数器T0、外部中断INT0以及相关硬件电路组成的自适应燃料点火器。这种点火器能根据燃料转化开关的位置,通过单片机控制实现对两用燃料汽车不同点火提前角的精确控制。试验结果表明:安装这种自适应燃料点火器的发动机功率、扭矩增大,能耗下降,这种自适应燃料点火器能够一定程度地提高两用燃料汽车发动机的动力性和燃油经济性。 相似文献
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This paper presents the system modeling, control strategy design, and experiment validation of a parallel hybrid electric bus with an automatic manual transmission (AMT) and a dry clutch. The mathematical model representation and the system architecture of the powertrain are first described. Next, a complete control scheme including energy management strategy and coordinated control of the AMT and the clutch is presented. The controller and powertrain models are then integrated in a way that the power management and the hybrid driveline perform in real world. The analysis and validation through model simulation and comparison with experiment data are conducted. A good agreement between the model and experiment demonstrates the efficacy and credibility of the integrated model. The integrated model is employed in both simulation and bench-test assessments for the development of a hybrid control unit. The results indicate that the model-based design methodology is beneficial to systematically analyzing and understanding the dynamics of hybrid electric powertrain. 相似文献
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J. Hur 《International Journal of Automotive Technology》2010,11(4):593-600
Motorization in vehicles is expanding rapidly for fuel efficiency, customer comfort, convenience, and safety features. These
new electric loads represent an increase in the required electric power. This has generated interest in new, higher power
systems such as the 42V Power Net. The electro-hydraulic power steering (EHPS) system is one of these systems. This paper
presents the development of the electric motor-driven pump unit for the EHPS system using a 42V power-Net. The interior type
permanent magnet synchronous motor (IPMSM) can be applied to this system with more power density per volume for compactness
of the EHPS. In order to improve the system, the IPMSM and its control method was optimized for improved torque characteristics
and electric power consumption. The performances of both the pump unit and the IPMSM have been verified by experimental results.
Finally, all in one type the electric motor-driven pump unit are developed from the experiment verification. 相似文献
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Korea is currently experiencing a rapidly increasing distribution rate of in-vehicle display devices, such as navigation or DMB displays, owing to remarkable advances in IT. At the same time, the number of traffic accidents and traffic violations is increasing due to the distraction of drivers’ attention by such devices. In particular, in-vehicle display devices such as navigation systems temporarily distract drivers’ visual or cognitive attention when they perform a unit task. Accordingly, it is necessary to prepare adequate standards to regulate in-vehicle display devices, especially in Korea. There are few empirical studies that have employed experiments to support such regulation. In this study, an experiment was conducted using a driving simulator to establish the proper standards regarding the maximum distraction time per unit task that can be allowed without causing any disturbance in safe driving. A total of 25 participants participated in the experiment. The distraction time was controlled by asking participants to perform the two tasks at once: while participants were driving as a primary task, they performed secondary task that count the number of intersections between the start point and the arrival point displayed on the screen. The results showed that the 2.0 second condition differed from the controlled condition in the deviation in the distance from the preceding vehicle, speed, and steering wheel movement, whereas there were no differences between the controlled condition and the 1.0 or 1.5 second condition. Finally, the limitations of the study and the implications of the findings with regard to future studies and application of the Korean version of guidelines for in-vehicle display devices are discussed. 相似文献
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