共查询到20条相似文献,搜索用时 812 毫秒
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Milan APETAUR Franti ek OPI KA 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1991,20(1):3-19
From a vibrational point of view, real vehicles form dynamic systems containing non-rigid bodies and nonlinear two-force elements, often excited by stationary random processes. Their theoretical investigation in a broader frequency range is practically possible in the frequency domain only. In the treatment of nonlinearities second-order stochastical linearization methods can be used advantageously. The amount of necessary computations can be vastly reduced by using known receptance matrices of all bodies in the system in its equations of motion after Fourier transformation. The article describes the receptance properties of non-rigid bodies, their use for the determination of the dynamic system's transfer functions and the determination of the output processes' spectral density matrix under stationary random external excitation using stochastical second-order linearization of the nonlinearities. 相似文献
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路面随机激励下的汽车非线性悬架系统振动分析 总被引:1,自引:0,他引:1
基于滤波白噪声生成法模拟了路面不平度,建立了四分之一车辆悬架系统非线性模型,在此基础上利用统计线性化方法对汽车非线性随机振动时域响应进行了研究,并利用MATLAB/Simulink软件对悬架振动进行了数字仿真。计算结果表明,用统计线性化方法求解汽车悬架系统的非线性随机振动问题是可行而且可靠的,仿真输出量可作为评价汽车平顺性的依据。 相似文献
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Milan APETAUR 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1991,20(5):309-320
Output force of a nonlinear two-force-element (TFE) excited by a stationary random process is stationary random as well and is described by its autocorrelation function.
Dependence of this autocorrelation function on the autocorrelation functions of the excitation process and of its velocity and on their crosscovanance function is indicated by the linearization (describing) function.
This paper describes the determination of the linearization function for a complex TFE composed of a parallel spring and damper, both having characteristics described by polynosmial functions. Knowledge of the linearization function is necessary for carrying out the second order linearization procedure of nonlinear dynamic systems excited by stationary random processes described in '1', '2', '3'. 相似文献
Dependence of this autocorrelation function on the autocorrelation functions of the excitation process and of its velocity and on their crosscovanance function is indicated by the linearization (describing) function.
This paper describes the determination of the linearization function for a complex TFE composed of a parallel spring and damper, both having characteristics described by polynosmial functions. Knowledge of the linearization function is necessary for carrying out the second order linearization procedure of nonlinear dynamic systems excited by stationary random processes described in '1', '2', '3'. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):309-320
Abstract Output force of a nonlinear two-force-element (TFE) excited by a stationary random process is stationary random as well and is described by its autocorrelation function. Dependence of this autocorrelation function on the autocorrelation functions of the excitation process and of its velocity and on their crosscovanance function is indicated by the linearization (describing) function. This paper describes the determination of the linearization function for a complex TFE composed of a parallel spring and damper, both having characteristics described by polynosmial functions. Knowledge of the linearization function is necessary for carrying out the second order linearization procedure of nonlinear dynamic systems excited by stationary random processes described in ‘1’, ‘2’, ‘3’. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(1):501-524
SUMMARY Vertical seat-suspension systems are characterized by a generalized two- degree-of-freedom model incorporating nonlinearities due to shock absorber damping, linkage friction and bump stops. The analytical model is validated using the results obtained from laboratory tests performed under sinusoidal excitations in the 0.5-8.0 Hz frequency range. Human body models of varying complexities, derived from the mechanical impedance data, are discussed and integrated to the nonlinear seat-suspension model to derive a coupled driver- seat-suspension model. Nonlinear analytical models are expressed by their linear equivalent models using a local equivalent linearization technique based on energy similarity. The vibration attenuation performance characteristics of the seat-suspension and driver-seat-suspension models are investigated for deterministic and random cab floor excitations. The results of the study revealed that the seated human body contributes considerably to the overall ride performance. 相似文献
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Mats Berg 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1998,30(3):197-212
A non-linear, dynamic rubber spring model is proposed. It mainly aims at representing the mechanical behaviour of rubber suspension components in rail vehicle dynamics. The model is one-dimensional, has five parameters and is based on a superposition of elastic, friction and viscous forces. The model is implemented in the computer packages MATLAB and GENSYS. Comparisons between model and measurement results for harmonic excitations show good agreement. A procedure to determine the model parameters from only two measured force-displacement loops is described. The model represents a reasonable compromise between accuracy and computational effort and should be a suitable tool in rail vehicle dynamics analysis. 相似文献
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I. Besselink F. Van Asperen 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1994,23(1):53-70
The demands upon the dynamic behaviour of a vehicle can be stated as an optimization problem. The optimum solution is calculated using an iterative optimization algorithm. Scaling the problem by non-linear transformations reduces the number of iterations. Lagrange multipliers provide useful information about the sensitivity of the optimum with respect to changes of the constraints. The analysis of the dynamic behaviour is performed in the frequency domain. New structural variants are calculated using system synthesis. As an example, the engine, cab and wheel suspension systems of a tractor/semi-trailer have been optimized all together. 相似文献
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Zhiwei Wang Zhonghui Yin Yao Cheng Guanhua Huang Hangyu Zou 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(4):543-563
In this study, we developed a comprehensive three-dimensional vehicle–track coupled dynamics model considering the traction drive system and axle box bearing. In this model, dynamic interactions between the axle box bearing and other components, such as the wheelset and bogie frame, are considered based on a detailed analysis of the structural properties and working mechanism of the axle box bearing. A few complicated dynamic excitations, such as the time-varying mesh stiffness of gears, time-varying stiffness of bearing, bearing gaps and track irregularities, are considered. Then, the dynamic responses of the vehicle–track system are demonstrated via numerical simulations based on the established dynamics model. The results indicate that the traction drive system and track irregularities can significantly influence the dynamic interactions of the axle box bearing. The necessity of considering the excitation caused by gear meshing and track irregularities when assessing the dynamic performance of the axle box bearing is demonstrated. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3-4):213-227
SUMMARY Computer-aided dynamic simulations are usually employed when designing modern urban railway vehicles. Even if the modeling procedure is similar to the one used for trains, specific features have to be taken into account for tramways: they are designed for low speeds (less than 80 km/h) and narrow curves (less than 20 m of radius). Moreover, in order to improve accessibility, low floor designs have been developed (the floor lying at about 300 mm above the rails level). The simulation procedure has therefore to take account of the occurence of multiple wheel/rail contacts or the modelization of independent wheels. A specific software well adapted to the computer-aided design of urban railway vehicles has been developed by the Faculte Polytechnique de Mons. It performs the following classical analyses: lateral linearization, modal analysis and root locii plots; vertical linearization and comfort prediction; non-linear time simulation in straight track (limit cycles) and in curve (derailment study) parametric analyses The vehicle model is formed by combination of bodies ( or flexible bodies, rotating bodies like wheelsets or independent wheels) and interconnection elements ( spring and damper elements). Contact between rails and wheels is treated as a part of the rotating bodies. A residual formulation has been preferred. When combined with the use of a complete iteration matrix, this formulation is well adapted to the treatment of stiff differential equations. It is based on a fast determination of the residues of the dynamic equations combined with the calculation of the iteration matrix through a numerical derivation procedure. The advantages of the approach are discussed. The model of a partial low floor vehicle with wheelsets and independent wheels is described. 相似文献
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汽车动力总成三点式悬置系统的设计方法探讨 总被引:4,自引:1,他引:3
首先分析汽车动力总成一悬置系统的振动激励、质量矩阵、刚度矩阵各元素的特点及其相互关系,阐释了系统弹性解耦设计的理论基础和重要性。然后根据动力总成一悬置系统刚度矩阵各元素的解析表达式,应用V形悬置组的弹性解耦原理,论述了目前普遍应用的三点式悬置系统在弹性解耦设计方面的问题,提出了悬置布置设计匹配的有效方法。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):725-758
SUMMARY This paper presents the results of a parametric sensitivity analysis of a five-axle tractor-semitrailer vehicle combination using 3-DOF linear yaw/plane model. The first order logarithmic sensitivity functions are derived with respect to several vehicle design parameters. For stabilization of the vehicle's directional behaviour a fairly new control concept called “Active Unilateral Braking Control (AUBC)” acting on the tractor rear wheel's in order to produce a stabilizing yaw torque is investigated. The AUBC system improves not only the directional stability, but also affects the roll dynamics of the vehicle. The sensitivity of the controlled vehicle system with linear quadratic controller (LQR) is also examined, a robust controller design procedure is proposed as a result of the sensitivity analysis. The robustness of this controller in the presence of both internal (including parametric uncertainties, non-linear dynamics) and external disturbances (such as road irregularities and side wind) allows its implementation with confidence with a non-linear vehicle model. The applicability of this control system to a non-linear vehicle model is tested using a 34 DOF, non-linear vehicle model of the tractor-semitrailer combination. 相似文献
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主动汽车悬架的非线性控制 总被引:8,自引:0,他引:8
本文采用1/4车模型对天棚阻尼器和主动悬架的动力学性能进行分析,针对执行器的非线性特性,探讨了微分几何法和反馈法线必互法在主动悬架控制中的应用,在系统控制设计中采用了离散滑模法,仿真结果显示非线性控制律能有效地改善主动悬架的隔振特性。 相似文献
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L. Palkovics M. El-Gindy 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(10):725-758
This paper presents the results of a parametric sensitivity analysis of a five-axle tractor-semitrailer vehicle combination using 3-DOF linear yaw/plane model. The first order logarithmic sensitivity functions are derived with respect to several vehicle design parameters. For stabilization of the vehicle's directional behaviour a fairly new control concept called “Active Unilateral Braking Control (AUBC)” acting on the tractor rear wheel's in order to produce a stabilizing yaw torque is investigated. The AUBC system improves not only the directional stability, but also affects the roll dynamics of the vehicle. The sensitivity of the controlled vehicle system with linear quadratic controller (LQR) is also examined, a robust controller design procedure is proposed as a result of the sensitivity analysis. The robustness of this controller in the presence of both internal (including parametric uncertainties, non-linear dynamics) and external disturbances (such as road irregularities and side wind) allows its implementation with confidence with a non-linear vehicle model. The applicability of this control system to a non-linear vehicle model is tested using a 34 DOF, non-linear vehicle model of the tractor-semitrailer combination. 相似文献
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Mattias M. Sj berg Leif Kari 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2002,37(3):217-236
A non-linear rubber isolator included in a dynamic system is examined where influences of dynamic amplitude and frequency are investigated through measurements and modeling. The frequency dependence of the isolator is modeled by a fractional calculus element while a frictional component accounts for its amplitude dependence. The model works in the time-domain and simulations of harmonic and non-harmonic motion are compared to measurements. Good agreement is obtained in a wide frequency and amplitude range for a freely oscillating one degree of freedom system, with the isolator acting as a coupling between exciting foundation and mass, and for a single isolator showing the typical amplitude dependence known as the Payne effect. The model is found to be superior to the commonly applied Kelvin-Voigt element in modeling the dynamic isolator properties. 相似文献
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Lei Xu 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(3):444-469
A stochastic mathematical model is developed to evaluate the dynamic behaviours and statistical responses of vehicle–track systems when random system excitations including crosswinds and track irregularities are imposed. In this model, the railway vehicle is regarded as a multi-rigid-body system, the track system is modelled by finite element theory. These two systems are spatially coupled by the nonlinear wheel–rail contact forces and unsteady aerodynamic forces. The high efficiency and accuracy of this stochastic model are validated by comparing to the robust Monte-Carlo method. Numerical studies show that crosswinds have a great influence on the dynamic performance of vehicle–track systems, especially on transverse vibrations. When the railway vehicle initially runs into the wind field, it will experience a severe vibration stage, and then stepping into a relatively steady state where the fluctuating winds and track irregularities will play deterministic roles in the deviations of system responses. Moreover, it is found that track irregularities should be properly considered in the safety assessment of the vehicle even in strong crosswinds. 相似文献