Time-frequency characteristics of the strain signal of the metal shell under internal explosion

Abstract

In this paper, the empirical mode decomposition-Hilbert Huang transform (EMD-HHT) was used to characterize the strain signal within metal cylindrical shell structure under internal blast loading. The received vibration frequencies of signal were closely consistent with FT characterization results. Through the EMD-HHT, instantaneous energy spectrum, marginal energy spectrum and Hilbert energy spectrum were determined, and these reflected the change in trend of signal energy in time domain, frequency domain, and time-frequency domain, showing the instantaneity and locality of explosion signal. The frequency components of the signal at any time were also determined, which proved that signals generated by the metal shell were the result of the superposition of different frequency signals under internal blast loading. This paper explains more clearly the time and frequency characteristics of blast signal, providing the theoretical basis for the study of antiknock in structures.