Rotating machines are widely used in various industrial sectors. Their dynamic characteristics are normally given a lot of thought throughout the design process, especially when crack incidence is taken into account. The influence of a transverse crack in a rotor system on its dynamic behavior was explored in this study. To identify the dynamic parameters of a rotor in terms of vibration responses, natural frequencies, and critical speed, the job entails constructing a numerical model based on displacement-based finite element technique. In building the model, varied fracture depths at different positions along the rotor were taken into account. To test the validity of the developed approach, a numerical example of a rotor system was used. The numerical results demonstrate a distinct shift in the cracked rotating machine's vibration responses, natural frequencies, and critical speed. The size and form of the alteration were discovered to be a function of crack volume and location. The findings suggest a potential tool for an on-line diagnosis and monitoring system.