某车型车内振动噪声传递路径分析与优化

发布时间：2018-07-14 20:12

【摘要】：在国内汽车市场稳步发展的环境下,人们对汽车的NVH性能越来越关注,车辆的NVH性能已经成为评判一辆汽车的关键。此外,SUV车型需要在非铺装路面上具有一定的行驶能力,因此车内良好的振动噪声水平将会更有利于驾驶员专心操作,提高安全性。本文基于传递路径分析法通过实车试验与有限元仿真相结合,对车辆发动机激励引起的车内振动噪声进行分析,并预测车内的噪声水平。在半消声室内测试车辆怠速和全油门工况下的响应以及解耦动力总成下测点间的频率响应函数。测试结果表明:在怠速工况下车内的振动噪声水平满足设计要求,但在全油门工况下车内噪声在2500r/min和4000r/min时噪声出现明显峰值。采用逆矩阵法对发动机激励点载荷进行计算并验证结果的有效性。建立白车身有限元模型,分析车身自由模态,并与验证后的白车身试验模态进行对比,结果表明:车身有限元模型准确、可信。将激励点载荷作为输入,对车身有限元模型进行频率响应分析,得出全油门工况下1号排气吊钩Y向和后悬置Z向为噪声峰值主要影响因素。通过频率响应函数和载荷的分析,针对副车架增加支撑,并分析优化后车内声学响应。结果表明:全油门工况下车内噪声峰值下降3-5d B(A)。说明采用本文方法对车内噪声水平的提升具有明显效果。
[Abstract]:With the steady development of the domestic automobile market, people pay more and more attention to the NVH performance of the vehicle, and the NVH performance of the vehicle has become the key to judge a vehicle. In addition, SUVs need to have certain driving ability on the non-pavement, so a good vibration and noise level in the vehicle will be more conducive to the driver to concentrate on the operation and improve safety. Based on the transfer path analysis method, the vibration noise caused by vehicle engine excitation is analyzed and the noise level in the vehicle is predicted by combining the real vehicle test with finite element simulation. The response of the vehicle under idle and full throttle conditions and the frequency response function between the measured points under the decoupling power assembly are measured in the semi-muffled chamber. The test results show that the vibration and noise level in the idling condition can meet the design requirements, but the noise in the whole throttle condition has obvious peak in 2500r/min and 4000r/min. The inverse matrix method is used to calculate the excitation point load of the engine and the validity of the results is verified. The finite element model of the white body is established, and the free mode of the body is analyzed. The results show that the finite element model of the body is accurate and credible. The excitation point load is taken as input and the frequency response of the finite element model of the body is analyzed. It is concluded that the Y direction and the backward Z direction of the No. 1 exhaust hook are the main factors affecting the peak noise under the full throttle condition. Through the analysis of frequency response function and load, support is added to the subframe, and the acoustic response of the vehicle is analyzed after optimization. The results show that the peak noise of the whole throttle is reduced from 3 to 5 dB (A). It shows that the method of this paper has obvious effect on raising the noise level inside the vehicle.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U467.493

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