An application of statistical tools in the identification of the transient vibrations of bucket-wheel excavators under random loads

Abstract

Due to fatigue cracks appearing in atypical places at construction of bucket-wheel excavator’s body, it was supposed that they are a consequence of transient vibrations associated with impulse loadings. This work presents a procedure for identification of such phenomenon. Operating loadings as well as vibration of bucket-wheel excavators’ structures are strongly random and nonstationary, what makes any analysis difficult. Moreover they reveal continuous changes in the structure of the frequency spectrum. For that reason the procedure was based on statistical measures and relativity of power spectral densities of vibration in succeeding time periods. As a result it was found that indeed transient vibration accompany impulse loading, but it isn’t full correlation, and it also happens for quite low impulses.