Coherent composite HOS analysis of rotating machines with different support flexibilities

Earlier studies have shown the possibilities of detecting different faults on a rigidly supported rotating machine through coherent composite spectrum (CCS) and coherent composite bispectrum (CCB) data fusion techniques. The current paper is also related to the use of CS, CB and a newly introduced coherent composite trispectrum (CCT) for faults identification in flexibly supported rotating machines. Six experimentally simulated cases have been considered on two sets of flexibly supported (FS1 and FS2) rotating machines, at 1,200 RPM (20 Hz) speed. Vibration data were then collected from both FS1 and FS2, using only four accelerometers (one per bearing pedestal in the diagonal direction), for the computation of CCS, CCB and CCT. Some combinations of CCB and CCT components were then used to further test the robustness of the techniques in rotating machines’ faults differentiation. The observations and results of the experiments are hereby discussed here.