Detection of two cracks in a rotor-bearing system using amplitude deviation curve

The dynamics and diagnostics of cracked rotors have been gaining importance in recent years. Relatively few authors have addressed the problem of multi-crack assessment for rotors. In many cases there exist more than one crack on the shaft. Then the solutions or the combinations of parameters characterizing the cracks are more and the problem becomes more complicated. In this study, a new technique called amplitude deviation curve (ADC) or slope deviation curve (SDC) has been developed, which is a modification of the operational deflection shape (ODS). The effectiveness of the SDC over ODS for small cracks detection has been demonstrated in the present paper.