共查询到20条相似文献,搜索用时 140 毫秒
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以某型客车白车身的试验模型和车门车窗的有限元模型求取结构模态信息,获取结构20~200 Hz的振动速度特性后,建立车内空腔的边界元模型.在LMS Virtual.Lab中计算声学传递向量特性,从而进行车身板件声学贡献分析,得出各板件对车内场点总声压的贡献度,并找出对车内某点声学贡献大的板件.通过实施改进措施,改善了该车车内噪声水平. 相似文献
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微型客车车内噪声试验研究 总被引:2,自引:0,他引:2
系统研究某微型客车因发动机、传动系振动及路面不平度激励引起的车内噪声的控制问题,通过试验分析,识别了主要声源,研究了车内声传递特性,确定了对车内噪声有较大贡献的车身板件,为进一步改善该车的声学特性而进行优化设计提供了基础。 相似文献
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在应用声传递向量技术对某商用客车的车内噪声进行板件声学贡献分析的基础上,提出了引入特征频率计权系数和场点权重系数确定多特征频率下对车内综合声场声学贡献量最大的关键车身板件的方法。接着采用中心组合设计通过最小二乘拟合建立了以关键板件振速和1阶模态频率为目标,板件与阻尼层厚度为变量的非线性的响应面模型,通过优化确定了变量的最佳组合。优化方案的实车试验结果显示车内噪声改善效果明显。 相似文献
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在介绍车室声腔声学系统建模方法和声固耦合系统有限元方程式的基础上,针对某轿车建立了车室声固耦合有限元模型。利用Abaqus对白车身结构,车内声腔结构以及声固耦合模型进行了模态分析,并通过对耦合前后模型的模态对比,得到了对车身振动以及噪声影响最大的频率段。同时通过模拟实验条件对声固耦合模型施加正弦激励,得到车内噪声声压场分布,从而为以后车内NVH性能的改进提供了参考。 相似文献
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基于总贡献系数和的客车噪声源识别 总被引:1,自引:0,他引:1
《汽车工程》2017,(5)
针对大中型客车中复杂噪声源对场点的贡献量不能完全代表该噪声源对车内整体噪声贡献量的问题,提出了一种衡量多输入对多输出贡献量的方法。首先对某型客车车内噪声进行频谱分析,得到车内噪声信号特征,计算怠速工况下不同噪声源对不同场点的偏相干函数。接着通过车内声学模态试验,分析了该客车车内空腔声学固有频率。最后,基于偏相干函数提出了"贡献系数和"和"总贡献系数和"两个新的评价参数,并结合声学模态特征,评价进排气、发动机和冷风扇等各关键噪声源信号对整车噪声的贡献量以及相互之间的影响,确定了主要的噪声源和需要改进的噪声频段,为有效降低车内噪声提供了指导方向。 相似文献
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针对后视镜引起的前侧窗与车内气动噪声问题,采用计算流体力学(CFD)方法对某商用车进行车外后视镜区域数值模拟和车内噪声预测的研究。稳态分析采用RANS模型中SST(Menter)k-ω模型,瞬态分析采用基于SST(Menter)k-ω的分离涡模拟(DES);通过分析后视镜侧窗区域的稳态静压力与瞬态动压力、速度和涡量云图,揭示了因A柱后视镜而产生车窗表面的湍流压力脉动的机理;同时求解瞬态流场获得两侧车窗表面湍流压力脉动载荷。采用声学FEM方法将车窗表面湍流压力脉动作为边界条件来计算气动噪声的传播,基于车内声学空间不同频率的声压级云图分布规律,说明了车内气动噪声主要集中在中低频段和声压级最大的分布区域;驾驶员左耳旁声压级曲线展示了20-2500 Hz频段内声压级变化规律。最后进行实车道路滑行测试,证实了气动噪声在车速80-110 km/h时较为明显的结论;采用CFD结合声学有限元的方法可较为准确地预测车内100-2500 Hz气动噪声的声压级,为优化后视镜、降低驾驶室内气动噪声提供仿真和试验的技术方案。 相似文献
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车身结构振动与车内噪声耦合的研究 总被引:3,自引:0,他引:3
本文介绍了汽车车身结构振动和乘座室空腔内部噪声的模态分析方法,并利用声-固耦合理论对车身结构振动与车内噪声之间的耦合关系进行了研究,为降低由结构振动所引起的车内低频噪声提供了结构修改和声学修改的措施。 相似文献
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Identifying the components of a vehicle’s interior noise is important in many phases of the noise, vibration, and harshness
(NVH) development process. Many test methods that have been widely used in the automobile industry to separate noise sources
are based on system identification methods in the frequency domain. However, none of the frequency response function-based
methods can directly estimate the wind noise component. In this article, an analytical model for the interior noise level
based on a simple power law was developed. It was assumed that the mean squared acoustic pressure for the interior noise could
be obtained by summing up those of the wind noise, road noise, and background noise. The wind noise and road noise were further
assumed to depend only on wind speed and the vehicle’s driving speed, respectively, and to follow a simple power law. The
resulting analytical model includes five parameters that can be optimized for the vehicle and the road. The validity of the
model was verified by using data obtained from cruise tests performed on a proving ground for cruise speeds ranging from 40
km/h to 130 km/h. The model is applied to the overall and 1/3-octave bands of interior noise and is shown to describe the
data trends fairly well. For the test vehicle used in the present work, the overall mean squared pressures for the wind and
road noise components are shown to be proportional to the wind speed to the 5.8 power and to the driving speed to the 3.4
power, respectively. 相似文献
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车内噪声中的结构噪声是由车身结构振动与车内空腔声场的耦合产生的,传统的振动模态分析方法在针对车内噪声控制时由于没有考虑这种耦合特性而存在很大的局限性。在介绍结构—声场耦合模态分析方法的原理基础上,计算出了客车的结构、空腔和声固耦合的各阶模态频率和振型,据此分析了产生车内低频噪声的原因,并提出了具体的车身结构修改意见。 相似文献
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Prediction of interior noise by excitation force of the powertrain based on hybrid transfer path analysis 总被引:1,自引:0,他引:1
In the early design stage of a vehicle, simulation of interior noise is useful for assessment and enhancement of the noise,
vibration and harshness (NVH) performance. Traditional transfer path analysis (TPA) technology cannot simulate interior noise
since it uses an experimental method. In order to solve this problem, hybrid TPA is employed in this paper. Hybrid TPA uses
simulated excitation force as the input force, which excites the flexible body of a car at the mount points, while traditional
TPA uses the measured force. This simulated force is obtained by numerical analysis of the finite element (FE) model of a
powertrain. Interior noise is predicted by multiplying the simulated force by the vibro-acoustic transfer function (VATF)
of the vehicle. The VATF is the acoustic response in the compartment of a car to the input force at the mount point of the
powertrain in the flexible car body. The trend of the predicted interior noise based on the hybrid TPA corresponds very well
to the measured interior noise, with some difference due to not only experimental error and simulation error, but also the
effect of the airborne path. 相似文献
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Interior sound field refinement of a passenger car using modified panel acoustic contribution analysis 总被引:3,自引:0,他引:3
Panel acoustic contribution analysis (PACA) is a practical engineering tool for the reduction of interior structure-borne
noise in passenger cars. In this study, the current PACA method has been improved for sound field refinement of the entire
interior. Two new parameters, the “acoustic contribution sum” and the “total sound field contribution”, are introduced to
analyze the interior sound field characterized with multiple field points and sound pressure peaks, and to evaluate the integrated
acoustic contributions of auto body panels. In addition, a systematic methodology for automotive interior sound field refinement
is also proposed on the basis of the modified PACA method. An example of a passenger car model demonstrates the application
of the sound-field-refinement methodology and shows the advantage of using damping layers at optimum locations on the auto
body. The example also shows that the modified PACA method has practical significance for refining the interior sound field
and decreasing added mass in accord with the trend towards lightweight auto bodies. 相似文献
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