The applicability of the short-time Fourier transform (STFT) for fatigue data editing

This paper presents the fatigue data editing technique for accelerating the simulation of fatigue durability testing. This technique was performed by removing low amplitude cycles contained in the original signal in order to produce a shortened signal using the short-time Fourier transform (STFT) method. The transformation of time domain signal into time-frequency domain provides the energy distribution display with respect to the particular time and frequency information. In this study, low amplitude cycles were eliminated according to the cut-off level of the signal energy distribution in the time representation. The simulation results showed that, the edited signal contained at least 94% of the original fatigue damage in the 124-seconds edited signal, i.e. 78% of the original signal time length. Thus, it has been suggested that this shortened signal can then be used in the laboratory fatigue testing for the purpose of accelerated fatigue testing. Finally, this STFT-based fatigue data editing approach is also suggested to be an alternative technique in fatigue durability study.