Cross-spectrum of signals of vibrations and their application for determination of the technical condition of dynamic equipment

Abstract

The aim of the paper is to develop ranking techniques for dynamic equipment based on its technical conditions, the estimation of recovered resource value and the determination of critical points of time after which equipment operation has to be terminated. Accelerometer data, cross-spectrum for wave analysis and a TOPSIS-based method have been used to achieve the goal. The most significant result of the work is a method of estimating the technical condition of the equipment, which allows: 1) to perform the transition to condition-based equipment maintenance by predicting non-normative work time; 2) to plan preventive repairs; 3) to select performers for repairs and maintenance of equipment based on objective estimates of work quality. The importance of the results is as follows: 1) the application of multi-criteria ranking method allowed to make ranking according to the technical condition of the equipment units for which condition monitoring groups of sensors are used; 2) it is shown that equipment condition changing is non-linear and there are areas of accelerated degradation; when the latter ones are reached, an accelerated condition deterioration is encountered; 3) the application of the technique on the data simultaneously taken from four sensors has shown its ability to conduct a comprehensive estimation without reference to a specific type of failure in conditions when the data from individual accelerometers give different information about the failure due to the different distance from the problem area. The verification of the proposed theoretical results is carried out on the basis of operating time data before a bearing failure, as well as monitoring data on the operation of wind turbine gearboxes.