系统传递特性的扫频测试方法

TESTING METHOD OF TRANSFER PROPERTIES FOR SYSTEMS BY FREQUENCY-SWEEPING

采用扫频振动激励的方法 ,获取机械系统的动态特性 ,具有能量集中、扫频范围灵活、信噪比高、节省时间和成本等优点。依照瞬时功率谱密度的概念 ,以缓冲包装系统为例 ,用 VC++和 MATL AB编程 ,对数据进行处理 ,在三维空间描述了激励信号和响应信号的瞬时功率谱和频率、时间的关系 ,进而得到了系统的振动传递特性。然后用这些参数创建仿真的数学模型并将扫频信号输入 ,比较模型的输出与实际系统的输出二者的关系 ,验证了此法的可靠性。

The method of frequency-sweeping for vibrational testing in order to obtain the dynamic properties of mechanical systems has a wide range of advantages, including large accumulation of energy, flexible frequency range, high signal-to-noise ratio, shorter testing time and better cost efficiency. This article utilizes the concept of transient frequency spectrum density, to apply to the cases of cushioned packaging systems. The signal analysis is done with Visual C++ and MATLAB programming, in order to process the data to obtain the accurate 3D representation of the transient frequency spectrum of vibrational signals and response signals as functions of time and frequency. The vibration transmissibility curve is also derived. Using the derived parameters, mathematical models are established to analyze vibrational signals to predict the output. The computational results are compared with experimental results and found to fit well, thus further confirming the reliability of the methodology.