An electric motor, having an imbalance of Imb=1.5 kg.cm is mounted at the end of a steel beam as shown in Figure. The beam is observed to vibrate with large amplitude at the operating speed of the motor, which is w₁ = 2500 rpm. It is proposed to add a vibration absorber (k2, me in the Figure) to reduce the vibration of the beam. Determine the ratio of the absorber mass to the mass of the motor needed in order to have the lower frequency of the resulting system equal to N=80% of the operating speed of the motor. If the mass of the motor is mm 300 kg, determine the stiffness and mass of the absorber. Also find the amplitude of vibration of the absorber mass. Assume the mass of the beam is negligible.

An electric motor, having an imbalance of Imb=1.5 kg.cm is mounted at the end of a steel beam as shown in Figure. The beam is observed to vibrate with large amplitude at the operating speed of the motor, which is w₁ = 2500 rpm. It is proposed to add a vibration absorber (k2, me in the Figure) to reduce the vibration of the beam. Determine the ratio of the absorber mass to the mass of the motor needed in order to have the lower frequency of the resulting system equal to N=80% of the operating speed of the motor. If the mass of the motor is mm 300 kg, determine the stiffness and mass of the absorber. Also find the amplitude of vibration of the absorber mass. Assume the mass of the beam is negligible.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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