Earlier research studies have suggested the unified
vibration-based approach for fault diagnosis (FD) in identical
machines with different foundation flexibilities and multi-rotating
speeds. Intially the acceleration-based features were used for this
approach then further work optimised the approach by combining
acceleration and velocity features from vibration data for analysis.
However the optimised approach was only tested on the identical
machines rotating at different speeds below the machine’s first
critical speed. The current paper tends to observe the optimised
approach when applied to a test rig operating below and above the
machine’s first critical speed.