硕士论文－车辆噪声控制与材料参数测试方法研究.doc

┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 装 ┊ ┊ ┊ ┊ ┊ 订 ┊ ┊ ┊ ┊ ┊ 线 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 毕业设计（论文）报告纸 共 页 第 PAGE 1 页 车辆噪声控制与材料参数测试方法研究 应用物理学 吴仁广 指导教师：葛剑敏 [摘要] 使用CPB分析材料组合系统的隔声特性，当空腔深度为30mm，系统在中心频率200Hz附近产生共振，隔声频率特性曲线在该位置形成一个低谷；当空腔深度为40mm，隔声频率特性曲线在中心频率为160Hz位置形成一个低谷。并筛选出最佳的材料组合系统，从车辆内部到外部环境依次为：装饰板、1号吸声材料、40mm空腔、50mm列车材料。在条件允许下，应适当加大空腔的深度，可使共振频率移到实用频率范围以下。 使用FFT和CPB分析排气系统的消声特性，在转速为2500rpm时，消声效果不理想，试验测得该排气基频为83.4Hz。并通过分析排气噪声的频率-阶次图，得到排气系统噪声主要由两部分组成：低转速下，2阶和4阶噪声占主要部分；高转速下，气流摩擦噪声占主要部分，且随着转速的提高，摩擦噪声慢慢地掩盖了空气动力噪声。 [关键词] 材料组合 隔声特性 排气系统 消声特性 [Abstract] By Using CPB to analyze the sound insulation character, it show that when the cavity depth is 30mm, the sympathetic vibration exist around the centre frequency of 200Hz of the system, the frequency character contours of sound insulation represent a lowest value. While the cavity depth is 40mm, the lowest value is around 160Hz.according to these characters, the optimal group system can be determined, the order of the optimal group system from inside to outside of the car is as follows: decorate board, No.1 sound absorption, the cavity of 40mm, train material of 50mm.the resonance frequency can be acquired at a lower utility frequency bands by increasing the cavity depth at a permit grade. When using FFT and CPB to analyze the noise elimination of exhaust system, the effect is not so well when it is at a 2500rpm of rotate speed; here the fundamental frequency is 83.4Hz. the noise of the exhaust air system is made of two parts: second-order and forth-order noise play main part at a low rotate speed, while at the high rotate speed the main action of the noise is air current friction, and the friction become the main position instead of aerodynamic noise bit by bit with the increasing of the rotate speed. [Keyword] material combination insulation character exhaust system noise elimination 目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc165172503 车辆噪声控制与材料参数测试方法研究 PAGEREF _Toc165172503 \h 1 HYPERLINK \l _Toc165172504 1 引