某型越野车驾驶室减振降噪技术研究

发布时间：2018-06-02 08:44

本文选题：驾驶室结构 + 模态分析　；参考：《南京理工大学》2016年硕士论文

【摘要】：随着国内汽车行业不断壮大,重型越野车辆的发展也越来越受到相关厂商的重视,客户对重型越野车辆的性能特别是NVH性能的要求也越来越高。在越野路面、低俗工况下,路面激励导致的重型越野车车身结构振动是车内低频噪声的主要来源,因此,车身结构振动特性研究十分关键。本文在国内外车辆振动噪声分析控制流程的基础上,以越野车驾驶室作为研究对象,分析其振动特性和声学特性,针对敏感频率处内声场声压级较大的问题,应用优化设计理论,结合板块声学贡献和拓扑优化方法对车身板件进行优化计算,控制结构振动和结构噪声。对白车身进行试验模态分析得到的模态参数,对标所建立的白车身有限元模型理论模态分析得到的模态参数,验证有限元模型的准确性。再以越野车整车为对象进行道路载荷试验,获取车身对应连接点的加速度信号。以经过信号处理的加速度信号作为激励加载到验证过的车身有限元模型上进行频响计算与结果分析。在频响分析结果的基础上进行板块声学贡献分析,对比研究各板块贡献结果,得到需要优化的目标板件。在此基础上将该结构板块设置为添加自由阻尼层的复合结构,进行拓扑优化分析。根据优化结果重新设置板件复合结构,再次提交频响计算并进行优化前后车身内部噪声水平对比。
[Abstract]:With the development of domestic automobile industry, the development of heavy-duty off-road vehicles has been paid more and more attention by related manufacturers. Customers have higher and higher requirements for the performance of heavy off-road vehicles, especially the performance of NVH. In the off-road, the vibration of heavy off-road vehicle body caused by road excitation is the main source of low-frequency noise in the vehicle, so it is very important to study the vibration characteristics of the body structure. Based on the analysis and control flow of vehicle vibration and noise at home and abroad, this paper takes the cab of off-road vehicle as the research object, analyzes its vibration characteristics and acoustic characteristics, aiming at the problem of large sound pressure level in sound field at sensitive frequency. Based on the theory of optimal design, combined with plate acoustic contribution and topology optimization method, the optimum calculation of body plate is carried out to control the structural vibration and structural noise. The modal parameters obtained from the experimental modal analysis of the white body and the modal parameters obtained from the theoretical modal analysis of the established finite element model of the white body are verified to verify the accuracy of the finite element model. Then the road load test is carried out on the whole vehicle, and the acceleration signal of the vehicle is obtained. The frequency response was calculated and the results were analyzed by using the acceleration signal which was processed by the signal as the excitation and loaded into the verified finite element model of the body. On the basis of the results of frequency response analysis, the plate acoustic contribution analysis is carried out, and the results of each plate contribution are compared and studied, and the target plates that need to be optimized are obtained. On this basis, the structure plate is set as a composite structure with free damping layer, and the topology optimization analysis is carried out. According to the optimization results, the plate composite structure is re-set, the frequency response calculation is submitted again, and the internal noise level of the body before and after optimization is compared.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.81;U469.3

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