【作者】 王彬星；

【导师】 连小珉；

【作者基本信息】 清华大学 ， 机械工程， 2013， 博士

【摘要】 中国重型汽车正成为中国汽车产业在国际市场上最具竞争力的强势产业，但目前国产重型汽车的NVH（Noise,Vibration and Harshness）性能和国际先进水平之间仍存在一定的差距。研究重型汽车车内噪声的预测与分析方法，开发具有良好声学舒适性的国产重型汽车，不仅对我国的汽车工业具有重要的战略意义，对我国国民经济的高速稳定发展也具有重要的作用。本文针对某在研重型汽车车型，在较宽频率范围内建立驾驶室的声学仿真模型，以实现低频、中频和高频段的车内声压级预测；建立运行工况下车内噪声的声源贡献率分析模型，以找出车内噪声的主要噪声源。通过上述两方面工作，为下一步车内声场的分析和优化提供基础平台，以期提高驾驶室的NVH性能。本文首先根据各种工况下实测车内噪声信号的能量分布情况，确定了研究的频率范围，然后按照从简到繁、循序渐进、逐一验证的原则依次建立了重型汽车白车身的有限元模型和整备驾驶室的有限元模型，并分别通过白车身模态试验和整备驾驶室的模态试验对模型逐一进行了验证。验证结果表明，建立的有限元模型可以用于下一步的驾驶室内声场仿真建模。基于经过验证的驾驶室有限元模型，综合利用有限元和边界元方法，建立了适用于低频车内声压级预测的有限元-边界元模型；综合利用有限元方法和统计能量分析方法，建立了适用于中频车内声压级预测的有限元-统计能量分析混合模型；利用统计能量分析方法，建立了适用于高频车内声压级预测的统计能量分析模型。三种模型均通过实车试验进行了验证。结果表明，在分析频率范围内的大部分频率点或频带内，驾驶员右耳侧声压级的计算值和实测值的误差在5dB以内。在建模过程中，主要研究和解决了各种数值计算方法的综合运用方法、不同结构和连接方式的合理简化和建模、约束条件的确定和施加、多种激励的确定和施加、统计能量分析模型参数的确定等问题，并提出了半消声室条件下多孔材料声学特性参数的识别方法，解决了基于对整体多孔材料的直接测量而识别其声学特性参数的问题，为驾驶室声学特性的正向设计提供了多孔材料的声学建模基础。为找出车内噪声的主要噪声源，建立了运行工况下车内噪声的声源贡献率分析模型。针对参考激励信号矩阵的病态程度随频率变化的具体情况，提出了基于分频能量相对拟合误差最小的混合求解法用于计算传递率矩阵，为车内噪声的声源贡献率分析提供了重要的计算工具。在此基础上，对各种工况下车内噪声的声源贡献率进行了分析，找出了主要噪声源。更多还原

【Abstract】 China’s heavy duty truck industry has been becoming increasingly morecompetitive in the international market. However, there still exists a certain gapbetween the NVH(Noise, Vibration and Harshness) performance of the national heavyduty truck and the international advanced level. To research the prediction and analysismethods of heavy duty truck interior noise and develop heavy duty trucks with betteracoustic comfort is not only of strategic significance to China’s automobile industry,but also of great importance to China’s national economy.The research object of this dissertation is the cab of the heavy duty truck indevelopment. The goal is to build different acoustic simulation models of the cab forthe prediction of the vehicle interior sound pressure level in different frequency rangesand to build operational vehicle interior noise source contribution analysis model toanalyze the noise sources’ contribution. The purpose is to provide a platform toanalyze and optimize the vehicle interior sound field so that the NVH performance ofthe cab can be improved.Firstly, the analysis frequency range is determined according to the energydistribution of the measured vehicle interior noise. Then the finite element model ofthe body-in-white cab and the finite element model of the complete cab are builtconsequently. The models are validated with the modal tests of the body-in-white caband the complete cab. The results show that the models can be used in the followinganalysis and modeling.Based on the validated finite element model of the cab, the finiteelement-boundary element model is built with the integrated utilization of the finiteelement method and the boundary element method to predict the vehicle interior noisein the low frequency range. The hybrid finite element-statistical energy analysis modelis built with the integrated utilization of the finite element method and the statisticalenergy analysis method to predict the vehicle interior noise in the middle frequencyrange and the statistical energy analysis model is built to predict the vehicle interiornoise in the high frequency range. All these models are validated with the measureddata under different operational conditions. It shows that for the most part of theanalysis frequency range, the difference between the calculated value and the measured value is within5decibels.In the modeling process, the research emphasis is focused on the integratedutilization of available numerical calculation methods,the reasonable simplificationand modeling of different structures and junctions, the determination and definition ofconstraints and various excitations, the determination of statistical energy analysisparameters, and so on. A method to identify the acoustic characteristic parameters ofporous materials in semi-anechoic chamber is put forward, so that the acousticcharacteristic parameters of porous materials can be identified based on the directmeasurement of the whole material and porous materials can be acoustically modeledin the top-down design of the acoustic characteristics of the cab.Operational vehicle interior noise source contribution analysis model based on thetransmissibility concept is built. For the problem of the condition number of thereference excitation matrix changing with the frequency, a calculation method basedon the criterion of the minimal energy relative fitting error in every frequency is putforward, so that the transmissibility matrix can be calculated with more accuracy. Mainsources of vehicle interior noise under different operational conditions are determined.更多还原