Vibrational Behavior and Dynamic Analysis of Cracked Rotor Systems During Transient Conditions
Abstract
The rotating shafts are an essential parts of any rotating machineries. Their dynamic behavior usually receives substantial care in the design stage of rotating machines, especially when the presence of crack is taken into account. The purpose of this paper is to investigate numerically and experimentally the influence of transverse cracks in rotating shaft on rotor dynamic behavior during transient conditions. The work comprises of developing a displacement–based finite element model for the cracked rotor to generate its dynamic characteristics represented in vibration transient response, natural frequency, and critical speed. Various crack depths located at different positions along the rotor were considered to design the numerical model. A numerical example was utilized to verify the validity of the developed model. In addition, an experimental apparatus was arranged to validate the developed computational model. The results obtained indicate that the presence of crack lead to a remarkable change in vibration response, natural frequency, and critical speed. The amount and nature of this change were observed to be varying with crack depth and location. Consequently, a novel model is proposed in this paper that suggests a possible approach for an online monitoring and diagnostic method for rotating machines.