等效约束下风激励汽车前侧窗玻璃声辐射分析

Sound Radiation Analysis of a Car Front Side Window Glass Under Equivalent Boundary Constraints and Wind Excitation

摘要:

为研究风激励下汽车侧窗玻璃表面湍流压力脉动激起玻璃振动而向车内辐射噪声的问题，以某试验车左前侧窗玻璃系统为研究对象，首先基于等效原理，将车窗密封条等效成系列弹簧约束，进行离散化建模，并搭建MatlabAbaqus联合仿真优化平台，得到最佳等效弹簧刚度，建立侧窗系统约束边界等效模型.接着利用Corcos模型计算得到侧窗表面湍流压力脉动的功率谱密度，作为侧窗等效模型的激励，应用有限元方法计算车内驾驶员人耳处的声辐射.最后应用激光测振仪，获得侧窗表面振动速度分布试验数据，利用边界元方法（半仿真）计算车内声辐射.比较两种方法的计算结果，发现200 Hz以上声辐射频谱特性吻合良好，证明了利用玻璃边界等效简化模型与Corcos模型作为激励源计算侧窗玻璃振动引起的声辐射有一定程度的适用性.

Abstract:

To study the mechanism of sound radiation induced by vibration of a car side window glass excited by wind turbulent pressure fluctuation, the front side window glass of a test car was considered in this paper. First, based on the equivalent principle, the boundary window seal was set equivalent to series of spring constraints to realize discrete modeling. Then, a MatlabAbaqus joint simulation optimization platform was built to obtain the best equivalent spring stiffness, so that an equivalent model of boundary constrains of side window glass system was established. After that, the power spectral density of the turbulence pressure fluctuation on the side window glass surface was calculated using the Corcos model, which was used as the excitation of the equivalent model to calculate sound radiation in driver’s ear position with FEM. Finally, a laser vibrometer system was applied to obtain the vibration velocity distribution of the side window glass surface, then the radiated interior noise was calculated with BEM method (semisimulation) based on the test data. A comparison of the calculation results of these two methods shows that the frequency spectra characteristics of sound radiation agree well with each other above 200 Hz, which demonstrates the usability of the calculation method of sound radiation based on the equivalent simplified model of side window glass system and the Corcos model as excitation source.