共查询到19条相似文献,搜索用时 156 毫秒
1.
基于逆变换的路面不平度仿真研究 总被引:25,自引:2,他引:23
针对使用现有方法仿真公路路面不平度时其结果存在误差的问题,研究了基于逆变换的路面不平度仿真的新方法。该方法直接研究给定的路面不平度功率谱密度,然后根据功率谱密度和离散FOURIER变换的性质以及信号采样定理,对数据进行截断、补充和一系列变换后获得路面的不平度。在考虑了汽车固有振动频率及行驶速度后。利用该方法对A、E两个等级的公路路面进行数值仿真。仿真结果显示:利用该方法所得路面不平度的功率谱密度与给定的功率谱密度准确一致,并且该方法简洁、便于使用。 相似文献
2.
利用计算机仿真技术预测车身零件疲劳寿命 总被引:6,自引:4,他引:6
为缩短新车开发周期、节约样本制造费用,本文提出了一种在计算机仿真环境中预测车身零件疲劳寿命的新方法。以某轻型客车为例,首先建立了该车的整体有限元模型。然后将采自试车场的典型路面谱作用于轮胎与路面 的接触点进行随机激励。不仅首次在计算机上模拟了汽车随机振动过程,而且得到了关键部位的加速度和动态应力响应及其相应的功率谱密度。最后,应用随机振动和疲劳累积损伤理论对仿真结果进行后处理,估算出该车在一定速度下连续行驶的疲劳寿命。其分析结果显示的危险部位与道路试验基本一致。 相似文献
3.
基于RBF神经网络识别路面谱的新方法 总被引:1,自引:1,他引:1
路面不平度是车辆行驶中振动的重要激励。为了识别路面不平度的功率谱密度函数(路面谱),提出了一种基于径向基函数(RBF)神经网络识别路面谱的新方法。该方法以7自由度汽车振动模型为基础,以MATLAB软件仿真得到的汽车车身质心垂直加速度谱为神经网络理想输入样本,以GB7031-86建议的路面谱为神经网络理想输出样本,应用RBF神经网络建立汽车车身质心垂直加速度谱和路面谱之间的非线性映射模型。另取一组仿真得到的车身质心垂直加速度谱代入已训练好的网络进行路面谱识别。结果表明:该方法具有较强的抗噪声能力和较理想的识别精度,识别的路面谱与拟合的路面谱吻合一致。 相似文献
4.
为研究时间和空间频率路面激励下重型车辆动载特性,将车辆的轮胎、钢板弹簧视为柔体,橡胶垫块、限位块简化为具有非线性刚度和阻尼特性的力元,采用多体动力学仿真软件SIMPACK建立刚柔耦合的车辆整车虚拟样机,并采用有理函数功率谱密度的谐波叠加法建立空间域和时域路面激励数学模型,创建一个时域和空间域路面激励下车辆行驶动力学模型,仿真计算了车辆各轴轮胎的法向作用力和车轮法向动栽系数.结果表明:不同车速下,时域和空间域路面激励下得到的轮胎法向作用力的变化规律和大小均不相同,而且轮胎法向作用力最大值出现的位置也不同;中、后轴车轮法向动栽系数变化规律基本相似,但前轴车轮法向动载系数变化规律不同.研究结果可为轮胎动载荷计算、验证、预测提供参考依据. 相似文献
5.
6.
为了研究车辆随机荷载作用下沥青路面的动力响应,建立了车辆随机振动模型和车辆随机激励下基层-面层双粘弹性沥青路面动力响应模型,并采用Fourier变换与小波变换相结合的新方法求得了路面随机响应解析解。根据实际车辆参数及道路参数,以路面不平度为初始激励,仿真得到了车辆随机荷载的功率谱密度函数和自相关函数,分析了沥青路面在车辆荷载下的随机动力响应特性,计算了沥青路面动力响应的主要数字特征函数,同时还对沥青路面随机动力响应进行了可靠性设计。结果表明:沥青路面动力响应的均值函数与路面等级无关,而自相关函数、功率谱密度函数及标准差均随着路面等级的下降而增加;采用提出的方法确定不同可靠度下不同等级沥青路面的动力响应值,可避免采用静载荷作为路面设计荷载的不合理性,为沥青路面的可靠性设计与分析提供参考。 相似文献
7.
8.
利用拓扑理论,对某国产轿车的整车拓扑结构进行分析,系统分析前后悬架子系统拓扑结构、转向子系统拓扑结构和动力总成拓扑结构并建立相应模型,结合Fiala轮胎模型和人椅系统模型,在ADAMS环境下建立了整车的虚拟样机,并编制随机的B级路面模型,研究在路面随机输入条件下该车的行驶平顺性。最后将该车道路试验结果与仿真结果进行对比,结果显示驾驶员座椅处垂向加速度功率谱的峰值所对应的频率一致,峰值大小略有差别,而垂向加速度功率谱变化趋势相同。 相似文献
9.
10.
介绍了把空间路面谱输入MTS汽车道路模拟机试验系统,以生成驱动信号,进行试验的基本原理和方法。利用此项技术,可使汽车道路模拟机具有了路面不平度谱输入试验的功能,为研究轮胎的包络特性及其它试验研究工作创造了条件。 相似文献
11.
Tire Modeling for Vertical Properties Including Enveloping Properties Using Experimental Modal Parameters 总被引:4,自引:0,他引:4
Fan Chengjian Guan Dihua 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,40(6):419-433
Summary Tire modal parameters reflect the natural properties of the tire. This paper models tire performance using experimental tire modal parameters to calculate the static vertical tire stiffness on both drum and flat road surfaces and the distribution of vertical and shear forces. The model was used to investigate tire enveloping properties. In addition to the radial and tangential displacements, the rotational angular displacement of the contact element is considered. This study examined the obstacle's effect on tire static vertical properties, the axle load responses under rectangle obstacles with a fixed axle height, and the effects of tire pressure on enveloping properties. 相似文献
12.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(6):419-433
Summary Tire modal parameters reflect the natural properties of the tire. This paper models tire performance using experimental tire modal parameters to calculate the static vertical tire stiffness on both drum and flat road surfaces and the distribution of vertical and shear forces. The model was used to investigate tire enveloping properties. In addition to the radial and tangential displacements, the rotational angular displacement of the contact element is considered. This study examined the obstacle’s effect on tire static vertical properties, the axle load responses under rectangle obstacles with a fixed axle height, and the effects of tire pressure on enveloping properties. 相似文献
13.
14.
N. Kang 《International Journal of Automotive Technology》2009,10(1):65-71
A lumped tire model was developed with consideration of the enveloping property in order to predict the natural tire frequency.
Tire stiffness was classified into vertical, sidewall, and enveloping stiffnesses, and the tire characteristics were analyzed
in detail experimentally and via finite element analysis. In addition, the effective masses of the tire tread and belt were
extracted directly from design specifications taking into account the sizes and material properties of different rubber blocks.
Using the design parameters of the tires, natural frequencies were calculated from the derived model and were compared with
experimental results. Finally, based on good agreement with experimental results, sensitivity analysis was performed to verify
the effect of tire stiffnesses on the natural frequencies. 相似文献
15.
为了提高仿真模型的计算效率,基于环模型理论系统研究了轮胎二维有限元模型的建模技术、参数确定方法和轮胎包容特性分析技术.从试验与仿真结果对比分析可知,利用有限元方法基于轮胎REF模型建模,在对轮胎胎侧弹性进行非线性模型修正后,得到的轮胎低速滚动仿真结果与试验结果基本吻合,验证了轮胎模型的有效性,同时为车辆一地面系统虚拟试验提供了一种实时高精度的轮胎面内特性仿真建模方法. 相似文献
16.
17.
Model-Based Road Friction Estimation 总被引:3,自引:0,他引:3
Taehyun Shim Donald Margolis 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2004,41(4):249-276
The tire/road friction coefficient, μ, has a significant role in vehicle longitudinal and lateral control, and there has been associated efforts to measure or estimate the road surface condition to provide additional information for stability augmentation systems of automobiles. In this paper, a model based road friction estimation algorithm is proposed from easily measured signals such as yaw rate and wheel speed. For the development of the estimator, a low order vehicle model incorporated with simple but effective tire model. Field tests of the estimator using actual vehicle measurements show promising results. 相似文献
18.
With the real time and accurate information of motor torque and rotation speed of the four-in-wheel-motordrive electric vehicles, a slip based algorithm for estimating maximum road friction coefficient is designed using Lyapunov stability theory. Modified Burckhardt tire model is used to describe longitudinal slip property of the tire. By introducing a new state variable, a nonlinear estimator is proposed to estimate the longitudinal tire force and the maximum road friction coefficient simultaneously. With the appropriate selection of estimation gain, the convergence of the estimation error of the tire longitudinal force and maximum road friction coefficient is proved through Lyapunov stability analysis. In addition, the error is exponentially stable near the origin. Finally the method is validated with Carsim-Simulink co-simulation and real vehicle tests under multi working conditions in acceleration situation which demonstrate high computational efficiency and accuracy of this method. 相似文献
19.
V. Alkan S. M. Karamihas G. Anlas 《International Journal of Automotive Technology》2011,12(4):529-535
To investigate static tire enveloping characteristics, a three dimensional (3-D) finite element model is proposed. The vertical
stiffness of the tire is studied on a flat surface with and without cleat. Tire rubber materials and cord layers are represented
independently using “rebar” elements available in MSC Marc Mentat. Comparisons of numerical and experimental results are given
to show the validity of the proposed model. It is shown that after a certain displacement, the results of the proposed model
agree well with experimental results. In addition, the model results show that regardless of the type of the cleat placed
under the rim center (hub center), all vertical force curves intersect after a certain displacement, which indicates typical
static enveloping characteristics. Moreover, another typical characteristic of the radial tires that is unlike those of bias-ply
constructions confirms that the contact patch does not expand laterally after a level vertical load is applied to the tire,
which is directly related to fuel consumption and tire tread life. 相似文献