vmd_energy

The faulty joint clearance sizes in the study are taken as 0.25 mm and 0.75 mm. The nonfaulty joint clearance size is guaranteed by fine machining (within 0.04 mm). Fifty groups of vibration data are measured per operation condition（normal condition and three mechanical fault conditions）. Therefore, 400 recordings of the three clearance joint faults and normal operating conditions are collected in the end. In the data file, the energy distribution are included. According to center frequency observations, the optimal number of intrinsic mode functions (IMFs) of VMD is selected as 5.  The original vibration is measured by two CCLD/IEPE shock accelerometers types 8339 with a measurement range of ±10000 m/s2, sensitivity of 0.25 mv/g, and upper cutoff frequency of 20 kHz are installed perpendicular to each other on the rack of the HVCB( types ZN12). A set of signal acquisition card types 3053-B-120 is adopted for vibration collection with a sampling frequency of 65536 Hz.