摘要
为降低车内低频噪声而改进车身结构时,现有方法往往需要较长周期,因此研究一种可快速、准确定位车身结构薄弱处,以及明确车身结构刚度调整方向的车身低噪声设计新方法。将一般腔体结构的内部声场计算公式分解为5个部分,并讨论这5个部分的特点,确定进行声压响应幅度判定参数研究时,采用的6种关键组合。以含一个弹性面的刚性长方体结构声腔耦合系统为对象,讨论6种关键组合的关系;分析发现振型耦合系数、频率重叠系数、结构振型在激励点处分量等三者的乘积能够完全体现声压响应信息,可作为声压响应幅度判定参数。详细分析声压响应幅度判定参数的特点,可满足预期研究目标;基于该参数,提出一种车身结构低噪声设计的新方法。利用该新方法,对某轿车车内低频噪声进行优化,进一步的频率响应计算结果表明,车身结构优化后驾驶员测点声压级平均降低3 dB,最大降低10 dB。
To control the interior low frequency noise of cars, body structure improvement is time consuming by existing methods. So one new design method of body to lower interior noise is studied, by which the weak region of body could be quickly and accurately located. And it also points out the adjustment direction of body stiffness. The analytical function of interior sound field of the cavity is divided into five parts. By analyzing their characteristics, the six key combinations are gotten for studying the determinant parameter of sound pressure Ievel（DPSPL）. A simple coupled system of a rigid box with one flexible wall is used to analyze the relationship among the six key combinations. Then it is found that the product of the mode shape coupling coefficient, the frequency overlap coefficient and the proportion of structure mode at the driving point, could stand for the interior sound pressure level. It is DPSPL of the simple coupled system. The features of DPSPL are discussed in detail which fulfill the expected objective. Then by DPSPL the new design method of body to lower interior noise is achieved. By the new method the interior sound pressure level of a car is lowered. The results of further frequency response analysis show that after improvements of body structure the sound pressure level at the driver＇s right ear is lowered by 3 dB on average and 10 dB at the most.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第12期96-102,共7页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划(863计划
2006AA110102)
中央高校基本科研业务费专项资金(XDJK2012C006)资助项目
关键词
车辆
车身结构声腔耦合系统
振型耦合系数
频率重叠系数
声压响应幅度判定参数
Vehicle Structural-acoustic coupled system of car body Mode shape coupling coefficientFrequency overlap coefficient Determinant parameter of sound pressure level
