An experimental and finite element investigation for determining critical speeds of a cracked jeffcott rotor model

Abstract

Rotating machines like pumps, compressors, generators, and steam and gas turbines are widely used in Industry 4.0. The researchers have gained more attention by modeling a cracked Jeffcott rotor system through a finite element approach. The present work consists of theoretical and finite element analysis of the Jeffcott rotor model with consideration of different crack depths, crack locations, and shaft material. Finite element results and their experimental verification obtained by FFT analysis show that increasing crack depth decreases the first critical speed of the system. Also, an increasing number of cracks results in decreases in the system’s first critical speed. The presence of a crack changes the stiffness of the shaft which results in, a decreasing the natural frequency. The present study approach provides an improved platform for crack diagnostic information to the vibration condition monitoring community for using Ansys software effectively as a finite element tool for performing rotordynamic analysis in Industry 4.0.