“…They have also received the attention of the structural dynamic researchers to detect non-linear behavior in structural dynamic response, for example -detection of transient signal [24], looseness at the support [22,25], breathing of a crack [26], a cubical (non-linear) stiffness in the system [23,27], faults in the anti-friction bearings, cracks and gears, etc. [28,29], and the use of the HOS in the monitoring of the machining process in manufacturing [30], the early contact detection between two structural components, [34] etc. However none of the earlier studies used the HOS in the rotating machinery for the fault detection.…”