【作者】 任开勋；

【导师】 沙云东；

【作者基本信息】 沈阳航空航天大学 ， 人机与环境工程， 2011， 硕士

【摘要】 本文针对飞机装配过程中铆接产生的高声强辐射噪声严重损害装配人员的听力系统,以及影响装配质量和工作效率等问题,研究了机身蒙皮铆接噪声产生机理、辐射特征和采用施加阻尼实现减振降噪的方法,重点利用数值计算方法模拟不同加载方式对振动响应和噪声的影响,以及施加阻尼对减振降噪的影响,并讨论了通过阻尼参数优化设置改进减振降噪效果的措施。首先,论文研究了机身蒙皮铆接噪声产生机理、辐射特征。压铆过程中薄板的振动响应是一个在大幅值短时间冲击力作用下的瞬态响应过程,在此过程中存在着铆枪在冷气驱动下的工作噪声、铆接头与铆钉之间的锤击噪声以及铆接头激励的结构件振动辐射噪声等类型。本文只研究结构振动辐射噪声和施加阻尼进行减振降噪的方法。主要采用了有限元和边界元相结合的方法,建立了薄板与支架在冲击载荷作用下的振动位移响应和结构声辐射特征计算模型,得到了节点的振动位移、固有频率和振动响应位移谱密度,以及辐射噪声的声功率和空间任一点的声压级。并详细讨论了不同边界、不同载荷、不同作用点对振动噪声的影响。在此基础上,建立了在薄板上施加自由阻尼层的动力学特性和响应计算分析模型,采用数值模拟方法计算了施加阻尼后结构的振动位移响应和声功率,分析总结了阻尼参数对结构振动位移响应的影响以及对辐射噪声的影响。综上所述,本文研究的飞机蒙皮铆接过程中冲击载荷作用下的结构振动辐射噪声以及阻尼减振降噪的数值模拟方法、计算结果以及分析结论对进一步开展先进阻尼减振降噪工艺装备的研制、提高装配质量和工作效率具有一定的参考应用价值。更多还原

【Abstract】 Against the problem that loud strong radiation noise oriented from riveting in assembling aircraft seriously damages the hearing system of assembler, and impacts the assembly quality and efficiency , this paper studies the mechanism of noise making in fuselage skin riveting, the characteristics of radiation and the method to reduce vibration and noise by imposing damping, which focuses on using numerical calculation method to simulate the impact on vibration response and noise of different loading ways, and the effect of reducing vibration and noise by imposing damping, as well as discussing measures to improve the efficiency of reducing vibration and noise by setting optimized damping parameters.Firstly, the paper studies the mechanism of noise making in fuselage skin riveting and characteristics of radiation. The vibration response of sheet in the process of pressing rivet is a transient response process under wide-amplitude and short-time impulsive force, in which there are working noise made by rivet gun driven by cold air, bumping noise from collision of riveting head and rivet, and radiation noise in structural vibration activated by rivet head, etc. This essay only researches structural vibration radiation noise and the method to reduce vibration and noise by imposing damping. It mainly adopts finite element and boundary element method, establishes the feature calculation model of vibration displacement response and structural acoustic radiation under the impact of buffet load of plate and bracket, and obtains the vibration displacement of node, natural frequency and spectrum density of vibration response displacement, as well as the sound power of radiation noise and sound pressure level of any point of space. It also discusses in detail the impact on vibration noise with different boundary, different load and different action point. On this base, It establishes calculation and analysis model of dynamic character and response by imposing free damping layer in the veneer, uses numerical simulation method to calculate the structural vibration displacement response and sound power after imposing damping, analyzes and summarizes the impact on structural vibration displacement response and radiation noise of different damping parameters. In a word, the structural vibration radiation noise under the impact of buffet load in the process of skin riveting in making aircraft, numerical simulation method using damping to reduce vibration and noise, the calculated results and analysis conclusions in this paper have a certain reference and application value in advancing technics and equipment using damping to reduce vibration and noise, and improving assembly quality and efficiency.更多还原