基于STFT的最大预示环境波形重构新方法

振动过程的最大预示环境(MEE)是指在某个关心的结构区域内,通过测量或预示手段获得的以谱形式表示的振动环境数据保守极限。然而,很多振动试验方法,特别是用振动台模拟低频瞬态环境时(低于100 Hz),需要给出试验信号的参考波形。文章结合振动模拟试验及短时傅里叶变换(STFT)时频分析,提出一种振动过程最大预示波形(MEW)的重构新方法。数值仿真结果表明,与传统方法相比,使用新方法重构的MEW误差更小,且试验控制更加灵活、高效,更适合于工程应用。

A new waveform reconstruction method based on STFT in the maximum expectant environment

The maximum expectant environment(MEE) of a vibration process means that in an area of a structure, the conservative limit of the vibration environmental data is obtained in the form of a spectrum by measurement or prediction methods. However, for many test methods, especially when the vibration table is used to simulate the low frequency transient environment (with frequency less than 100 Hz), the test reference signal waveforms have to be given. Based on the MEE of the vibration process besides the time and frequency analysis, a new method is proposed to reconstruct rapidly the maximum expectant environmental waveform(MEW) in the vibration simulation test. The numerical simulation results show that the error of the calculations by the new method is reduced, and the control is more flexible and efficient as compared with the traditional method, thus the new waveform reconstruction method can be used in the vibration environment test.