Dynamic Behavior Analysis of a Rotating Shaft with an Elliptical Breathing Surface Crack

Ahmed A. Elkashlawy , Younes K. Younes , Heba El-Mongy* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)
2 Downloads (Pure)


In this paper, dynamic behavior of a rotor system with an elliptical breathing crack that simulates the real shape of the crack front is investigated.

A finite element model of the cracked rotor system is developed. The crack breathing mechanism is modelled based on an improved breathing model which considers the inclination of the neutral axis of the cracked element cross-section during shaft rotation. Harmonic balance method is used to solve the equations of motion of the rotor system for steady-state response characteristics. The effect of some parameters such as crack depth, crack shape factor and the spinning speed is investigated.

Results and conclusions
The results show that the unique whirl orbits behavior during passage through the subcritical speeds serve as a key indicator of crack presence in the shaft. The effects of the crack front curvature and the breathing model are revealed. The value of shape factor affects the whirl orbit characteristics such as size of the inner or outer loops and the amount by which the orbits rotate while crossing the subcritical speeds. The presented model considering the real crack front shape may contribute towards improved modelling of cracked rotors and better interpretation of measured vibration response.
Original languageEnglish
Pages (from-to)4371–4385
Number of pages15
JournalJournal of Vibration Engineering & Technologies
Early online date8 Feb 2023
Publication statusPublished - 1 Nov 2023

Bibliographical note

Open access via the Springer Compact
The authors would like to thank the anonymous reviewers for their valuable suggestions that helped in improving the manuscript.


  • Elliptical crack
  • Crack breathing
  • Cracked rotor
  • Finite element analysis
  • harmonic balance method


Dive into the research topics of 'Dynamic Behavior Analysis of a Rotating Shaft with an Elliptical Breathing Surface Crack'. Together they form a unique fingerprint.

Cite this