传统路面噪声计算不考虑轮胎的影响,容易导致新能源汽车底盘系统噪声控制欠缺,使得仿真阶段噪声预测偏差较大.针对该问题,对轮胎进行模态测试,利用逼近计算生成仿真轮胎,结合底盘系统搭建整车路噪的仿真模型;利用实测路面噪声数据,对比模态轮胎法、传统轴心力荷载法的计算结果.结果表明:模态轮胎法比传统轴心力荷载法计算路面噪声峰值的计算精度高10.8百分点,尤其是对于轮胎的空腔噪声;与实测数据相比,A计权噪声仅有0.5～2.0 dB的计算误差.

In order to solve the problem of abnormal noise when the car is shifted,the dynamic model of transmission system with 7 degrees of freedom is established.The model contains flywheel,clutch,gearbox,transmission shaft,drive shaft and tire.Using the established mathematical model,natural frequency and main vibration shape of the transmission system can be obtained.With the help of Adams software to build a multi-body dynamics model of the transmission system,and then perform modal analysis calculations on the model,the main kinetic energy that affects the shift shock is concentrated in the flywheel,and the main potential energy is concentrated in the drive half shaft.Starting from the excitation,constructing the clutch vibration damping characteristic model,and analyzing the sensitivity of the clutch clearance angle,it can be concluded that the larger the clearance angle,the more obvious the shift shock.Therefore,the optimized design is carried out for the flywheel inertia,drive axle stiffness,and clutch clearance angle,and is installed on the real vehicle for verification.The results show that the shift shock of the vehicle is effectively improved by installing the optimized components.The established model and analysis method have guiding significance for improving the shift shock.

针对某款后驱车辆在运行过程中异常明显的车内轰鸣问题,对整车进行轰鸣试验,确认轰鸣振动的状态.同时,对该后驱车辆的传动系统进行台架扫频试验,以研究传动系统共振模态对轰鸣振动的影响.借助ADAMS软件搭建整车多体动力学模型,利用对标后的模型进行模态解析计算,对轰鸣振动的发生机理进行研究,进而制定改善轰鸣振动的方案,同时在实车上进行验证.结果表明:针对离合器刚度及传动轴振动的改善方案能够有效地解决后驱车辆的轰鸣问题.

全消声室是汽车NVH性能的研发、测试及改进的平台.自由场是声学试验室中的一个重要的性能指标,自由场半径大小决定着被测物体的大小,为了对全消声室中的自由声场进行计算,应用Raynoise软件对全消声室声场进行仿真计算,并利用ISO 3745-2012所规定的最大允许偏差进行了自由声场的鉴定.

Usually, the judgement of one type fault of vehicle pass-by noise is difficult for engineers, especially when some significant features are disturbed by other interference noise, such as the squealing noise is almost simultaneous with the whistle in the exhaust system. In order to cope with this problem, a new method, with the antinoise ability of the algorithm on the condition by which the features are entangled, is developed to extract clear features for the fault analysis. In the proposed method, the nonnegative Tucker3 decomposition (NTD) with fast updating algorithm, signed as NTD FUP, can find out the natural frequency of the parts/components from the exhaust system. Not only does the NTD FUP extract clear features from the confused noise, but also it is superior to the traditional methods in practice. Then, an aluminium-foil alloy material, which is used for the heat shield for its lower noise radiation, replaces the aluminium alloy alone. Extensive experiments show that the sound pressure level of the vehicle pass-by noise is reduced 0.9 dB(A) by the improved heat shield, which is also considered as a more lightweight design for the exhaust system of an automobile.

为解决传动系扭振所导致的MPV车内轰鸣声问题,以某型国产前置后驱MPV为研究对象,建立了传动系扭振AMESim仿真模型,利用飞轮端角加速度(实测数据)与飞轮及曲轴惯量乘积作为系统输入,激励模型进行强迫响应分析,通过对比关键点扭振仿真结果与试验结果从而验证了模型有效性,利用此模型研究了对象车型传动系扭振特性,从减少激振力输入的角度出发,提出了通过加装扭转减振器控制后桥输入轴处扭振幅值的方案.验证试验结果表明:所提方案可以有效地降低传动系扭振,改善提升车内声振舒适性,对车内轰鸣问题存在较好优化效果,从而解决了由于传动系扭振引发的NVH问题.

Theoretical analysis, experimental testing, and CAE simulation as three kinds of the power transmission system torsional vibration analysis methods are elaborated in detail, and the torsional vibration characteristics are analyzed for the microbus FR-type power transmission system. In this basis, the power transmission system torsional vibration control methods are summarized from dynamics parameters optimization and attached reduction&isolation vibration devices, including the analysis of dynamics parameters effecting to the power transmission system inherent characteristics and torsional vibration response, and comparing advantages and disadvantages and discussing engineering applications of TVD, CTD, DMF&STD.

In this paper statistically optimal acoustic array technology is applied to interior and exterior sound source identification of the car. An advanced far field acoustic hologram is proposed to improve the spatial resolution for low frequency sound source location in far field. Acoustic contribution based on near field acoustic hologram is analyzed in order to provide the direction of low noise control. The statistical optimal beamforming is used to identify high frequency sound source, and DAMAS is applied to achieve high spatial resolution in post processing. Then a new technology used to sound source location and low noise control is explored. Finally the proposed methodologies in this paper have been applied to a car to identify the interior and exterior noise source and analyze acoustic contribution.

The dynamics model for powertrain mount system is established,and the dynamics simulation is conducted with loading data obtained.Then powertrain mount bracket is analyzed using finite element method.Based on the results of analysis,a corresponding continuum structure topology optimization is performed on the bracket,with the mass of mount bracket reduced.

The interior noise is one of key performances of vehicle NVH.The aid of this passage is to tell the reader how to evaluate the separating and absorbing performance of the total vehicle interior decorations by using"full window"method.With this method using the octave map and front/back map to analyze the dates can find the contribution of the interior decorations to the interior noise.Using this method can improve the interior noise by modifying the interior decorations design.At the same time it's convenient to the carmaker's vehicle interior decorations develop.

经过对我司开发的五菱荣光发动机悬置支架进行整车NVH测试,在效果不佳的背景下,对悬置支架进行初步优化,主要是提高模态,以期提高隔振效果.经过再一次的NVH测试得出:悬置支架的隔振效果明显提高,并满足NVH要求.