150摩托车噪声测量及声源分析（本科毕业论文设计）.doc

150摩托车噪声测量及声源分析（本科毕业论文设计）

摘    要

摩托车噪声对人们生活、工作环境的影响越来越大，控制摩托车噪声已成为关系到人们生活、工作质量的一件大事。而且在摩托车技术水平大幅提高后的今天，噪声水平正逐渐成为人们评价摩托车等级水平的一个重要指标。摩托车噪声限值标准的日趋严格对噪声控制水平的要求不断提高，也推动了对噪声控制的研究。
噪声的声学特性决定了摩托车噪声主要取决于最大噪声源噪声大小，降低摩托车噪声的前提是利用现代检测技术,准确识别主要声源的部位、频率等特征,有针对性地采取有效措施进行降噪。
本文通过采用声强测试法分别对建设摩托150-A进行整车加速噪声和声强测试，然后使用LMS.TESTLAB 8A软件对实验数据进行噪声频谱特性分析，得到以下结论：以排气基频为主的低频噪声0-500主要集中在排气口处；中低频500-1000主要以发动机缸头处和链条连接处为主；2000-2400共振带为发动机的缸头处。对比各频段能量百分比和各声源的声强绝对值，最需要迫切消除的声源是排气噪声。

关键词：摩托车，噪声声源识别，声强，频谱分析

ABSTRACT

The influence to peoples' living and working environment by motorcycle noise is more and more serious, controlling of motorcycle noise has become an event which is related to the quality of peoples’ life and work. And, the motorcycle noise level has gradually become an important index of the eva luation on motor cycle as the technology of motor cycle manufacturing has increased. The standard of noise limit value has become more and more strict also promote the research of noise controlling.
Acoustic characteristics of noise decide that motor cycle noise depends mainly on the magnitude of biggest noise source, the precondition to decrease motor cycle noise is using modern measure technology, identify the location and frequency of main source and so on, then take corresponding measure to denoise
In this paper, according to Sound Intensity Measurement on JIANSHE MOTOR 150-A, then use LMS.TESTLAB 8A to take Spectrum characteristic analysis, and get the results:Low frequency noise 0-500 mostly located in exhaust port;Middle and low frequency noise 500-1000 mostly located in engine cylinder head;Resonance band 2000-2400 mostly located in the junction of chain.Comprise the energy percentage and absolute value of acoustic intensity in each frequency band, urgently need to eliminate is exhaust noise.

Keywords：Motor cycle; Recognition of noise source; sound intensity; spectrum analysis

 
 
目   录
摘    要 I
ABSTRACT II
1绪论 1
1.1 摩托车噪声概述 1
1.2摩托车噪声研究背景意义 2
1.3国内外研究现状 4
1.4本文研究内容 6
2.摩托车噪声源特性 7
2.1噪声的度量 7
2.1.1声压、声强、声功率 7
2.1.2噪声的频谱与频程 8
2.1.3噪声的计权分析 9
2.2摩托车噪声分析 9
2.2.1发动机噪声 9
2.2.2其他噪声 13
2.3本章小结 13
3.摩托车噪声源的识别方法 14
3.1常用的噪声源识别方法 14
3.1.1主观评价法 14
3.1.2近场话筒拾音法 14
3.1.3分别运行法 15
3.1.4铅覆盖法 15
3.1.5频率分析法 15
3.1.6定转速变功率频谱分析法 16
3.2声强测量法 16
3.2.1表面声强法 16
3.2.2双传声器法 16
3.3本章小结 18
4建设150-A摩托车噪声声源识别测试 19
4．1加速噪声测试 19
4.1.1实验方案 19
4.1.2 加速噪声测试结果分析 21
4.1.3加速噪声数据频谱分析 22
4.1.4加速噪声测试小结 23
4.2整车声强测试 23
4.2.1实验方案 23
4.2.2声强试验数据分析处理 25
4.2.3声强测试小结 29
4.3本章小结 29
5全文总结 30
参 考 文 献 31
致   谢 32