Load spectra analysis and reconstruction for hydraulic pump components

Hydraulic pumps are used as operating components in many mechanical systems (e.g. actuators in machines for moving materials) and, consequently, during their working life they are subjected to variable amplitude loadings. As this is the case, a thorough analysis of their load histories may be highly useful as it would help to determine an equivalent constant amplitude signal which could be easily applied to a test bench for the homologation of pumps. In the present paper, a novel methodology for the analysis of hydraulic pumps is suggested. The proposed methodology accounts for the different damaging processes of fixed and rotating parts of hydraulic pumps and applies both statistics of extreme values and the analysis of signals in the Markov domain. The results consist of block loadings, to be applied at the test bench, which represent extrapolated experimental signals measured on pumps during their service in different applications.