Hassan Jalali - Department of Mechanical Engineering, Arak University of Technology,۳۸۱۸۱-۴۱۱۶۷, Arak, Iran.
Farzad Rafieian, - Department of Mechanical Engineering, Arak University of Technology,۳۸۱۸۱-۴۱۱۶۷, Arak, Iran.
Majid Rajaei - Department of Mechanical Engineering, Arak University of Technology,۳۸۱۸۱-۴۱۱۶۷, Arak, Iran.

This paper reports on the results of a series of modal testing performed on an exciter rotor in Shazand thermal power plant. The rotor was suspected to have cracks or other types of dam-ages due to the shift observed in its first critical speed. The aim of doing modal testing is to monitor the health status of the exciter shaft by using its dynamic properties.

Rotor; The modal analysis; Crack; Condition monitoring.