共查询到19条相似文献,搜索用时 218 毫秒
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内燃机曲轴扭转振动的优化动力修改 总被引:1,自引:0,他引:1
利用集总参数法建立了曲轴扭转振动的运动方程,推导了计入结构参数的曲轴系统扭转振动的特征灵敏度公式,并给出了结构参数修改的优化模型。数值计算结果表明,根据此灵敏度公式和优化模型可更合理地确定结构参数的修改量,从而有效地进行曲轴系统的结构动力修改。 相似文献
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采用浸入边界-格子玻尔兹曼法建立密封系统流固耦合模型,研究不同预压缩量下的密封条隔声。利用浸入边界法建立密封条的力学模型,同时用格子玻尔兹曼法模拟周围流体,两者结合完成实际车门密封条系统的二维简化计算模型。通过比较动态载荷下有限元和浸入边界模型的模拟结果,验证了系统建模的有效性。设计并搭建密封条隔声试验台架,可测量不同预压缩条件下的隔声。试验与仿真的结果相互验证,结果显示,有效挤压下密封条隔声量随着预压缩量缓慢上升,而产生缝隙后隔声量将显著下降。研究证明浸入边界-格子玻尔兹曼法处理流固耦合建模简便且计算效率高,在汽车密封系统相关的失效、隔声、泄漏噪声等问题上有广泛的应用前景。 相似文献
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本文利用粘性减振器对微笄珠独立悬架转向轮的摆振及其阴尼控制进行了仿真计算分析和试验。首先,建立了该车转向系的5自由度集总参数摆振分析模型,通过一系列测试和计算确定了模型的各种参数。探索了利用计算机控制的电液伺服高频激振试验系统进行了整车转向系摆振实验分析的研究方法。 相似文献
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《公路交通科技》2021,(8)
为了探究突发事故条件下道路交通流早发性失效机理,采用尖点突变模型建立了交通流早发性失效分析模型。首先,将尖点突变模型变量与交通流参数一一对应,建立了交通流尖点突变模型与实际道路交通运行状态的映射联系,并针对系统状态控制点在平衡曲面上的运动路径与交通流状态演变过程进行了对应分析。随后,引入分叉系数、包围系数及失效阈值边界3个参数定量描述了分叉集,旨在全面、细致地刻画分叉集的特征,揭示分叉集特征对系统状态控制点运动路径的实际影响。基于实测数据,建立了同一路段上有、无事故2种场景下的交通流尖点突变模型,通过最小二乘法拟合得到模型相关参数,并以此为基础推导计算得到2种场景下分叉集的特征参数。采用定量与定性分析相结合的方式对2种场景下交通流系统的演变进行了对比分析,进而揭示了突发事故条件下交通流早发性失效机理,并提出了相应的早发性失效预测方法。最后,结合2种场景下短时交通流参数时序变化路径进行了验证性分析,证明了所采用方法的可行性及合理性。 相似文献
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智能交通系统中动态路径诱导算法分析 总被引:1,自引:0,他引:1
对智能交通中动态路径诱导算法进行较为系统的综述。首先,从微观和宏观角度对动态诱导系统中需要用到的交通参数模型进行分析和比较,并列举几种交通参数模型;然后,对一些经典路网寻优算法进行分析,并引用一些专家学者的研究成果;最后,对动态路径诱导算法的未来发展方向进行探讨。 相似文献
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Dynamic analysis of spiral bevel geared rotor systems applying finite elements and enhanced lumped parameters 总被引:2,自引:0,他引:2
X. Hua T. C. Lim T. Peng W. E. Wali 《International Journal of Automotive Technology》2012,13(1):97-107
The dynamics of spiral bevel gears like most high-speed precision gears employed in motor vehicles and off highway equipments
are substantially affected by the structural characteristics of the shafts and bearings. The lumped parameter model is one
of the common tools applied to perform gear dynamic analysis. Even though the lumped parameter approach is computationally
fast and conveniently efficient, it typically uses limited number of coordinates and may not fully account for the shaft-bearing
structural characteristics accurately. In this analysis, the finite element formulation, that can generally represent more
complete characteristics of the shaft-bearing assembly, is employed to enhance the current lumped parameter synthesis theory
using the concept of effective mass and inertia elements. Computational output shows that the enhanced lumped parameter synthesis
model is capable of predicting sufficiently accurate dynamic response when compared to the direct dynamic finite element calculations,
and much more precise response than previous lumped parameter results, especially when the gear dynamics are associated with
the pinion or gear bending modes. Even though this analysis focuses primarily on the spiral bevel geared rotor systems, the
proposed methodology and analysis results can be easily extended to other types of gears. 相似文献
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基于ADAMS的客车独立悬架的运动仿真 总被引:1,自引:0,他引:1
应用多体动力学软件ADMAS建立SX6123低入口公路客车的前空气独立悬架系统模型,通过对其进行运动学仿真分析,得到前轮定位参数随车轮跳动变化的关系曲线,为独立悬架系统的设计和匹配提供参考。 相似文献
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准确分析滑移门系统的动力学特性,对车用滑移门的工程开发具有重要意义。文章基于仿形门试验台进行滚轮力试验测量,采用联合仿真的DOE方法,对滑移门动力学模型中的滚轮导轨接触模型进行两因素、多水平组合寻优,获取满足滚轮力误差要求的最优接触力参数组合,并对滑移门动力学模型进行开启、关闭的仿真分析。研究表明,基于此方法建立的滑移门动力学模型具有较高的分析精度,中导轨前导向轮峰值力最大误差为7.52%,能够准确地模拟滑移门的滑动过程;0 °导轨滚轮力比带倾角的滚轮力显著增大,与试验现象完全一致。文章所建立的仿形门试验、动力学建模、参数识别以及动力学分析等流程,可支持滑移门多参数影响分析和平顺性评估,为滑移门正向开发提供有效的理论分析依据。 相似文献
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An accurate battery State-of-Charge (SoC) estimation method is one of the most significant and difficult techniques to promote the commercialization of electric vehicles. This paper tries to make two contributions to the existing literatures through a robust extended Kalman filter (REKF) algorithm. (1) An improved lumped parameter battery model has been proposed based on the Thevenin battery model and the global optimization-oriented genetic algorithm is used to get the optimal polarization time constant of the battery model. (2) A REKF algorithm is employed to build an accurate data-driven based robust SoC estimator for a LiFePO4 lithium-ion battery. The result with the Federal Urban Driving Schedules (FUDS) test shows that the improved lumped parameter battery model can simulate the dynamic performance of the battery accurately. More importantly, the REKF based SoC estimation approach makes the SoC estimation with high accuracy and reliability, it can efficiently eliminate the problem of accumulated calculation error and erroneous initial estimator state of the SoC. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1455-1479
Due to the intrinsic nonlinear characteristics and complex structure of the high-speed catenary system, a modelling method is proposed based on the analytical expressions of nonlinear cable and truss elements. The calculation procedure for solving the initial equilibrium state is proposed based on the Newton–Raphson iteration method. The deformed configuration of the catenary system as well as the initial length of each wire can be calculated. Its accuracy and validity of computing the initial equilibrium state are verified by comparison with the separate model method, absolute nodal coordinate formulation and other methods in the previous literatures. Then, the proposed model is combined with a lumped pantograph model and a dynamic simulation procedure is proposed. The accuracy is guaranteed by the multiple iterative calculations in each time step. The dynamic performance of the proposed model is validated by comparison with EN 50318, the results of the finite element method software and SIEMENS simulation report, respectively. At last, the influence of the catenary design parameters (such as the reserved sag and pre-tension) on the dynamic performance is preliminarily analysed by using the proposed model. 相似文献
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双腔室空气弹簧以其优良的隔振性能及刚度可变特性已经在部分高端车型和赛车上得到应用,但是对其动刚度预报的精确模型及动态特性的深入研究还不够完善。基于能量原理从热力学角度出发,结合空气动力学及结构动力学给出一套双腔室空气弹簧的精确模型并给出各刚度、阻尼项明确的物理意义。设计示功试验,选取不同振幅和频率的正弦激励对双/单腔空气弹簧进行试验验证。试验结果表明所提动刚度模型能够很好地反映出双腔室空气弹簧的滞回特性及刚度可变特性,也能够明确反映出动刚度的频率相关性。最后基于模型给出各参数项对动刚度幅值和滞回相位角的影响规律,基于试验验证仿真结果并给出规律的物理解释。研究结果表明:单腔室空气弹簧的动刚度频率特性相位角仅因热交换而存在一个峰值;双腔室空气弹簧的动刚度相位角存在2个峰值,主要是由热交换(第1峰)与小孔产生的阻尼效应(第2峰)导致;当激励频率趋向于无穷时,由于热交换不充分及腔室之间气体来不及进行交换,故单/双腔室空气弹簧的动刚度相位角逐渐趋向于零;研究得出的模型预报方法及动态特性可以对单/双腔室空气弹簧的动刚度进行准确估计,并给出了其动刚度的频率相关性及其影响因素与变化规律。研究结论能够对空气弹簧的整车动力学匹配及设计提供正面的指导。 相似文献
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