A reciprocating engine is installed on the fifth floor of a new building to provide ventilation services, which can be modelled as a rigid rectangular plate resting on four elastic columns. The total mass of the engine and floor is 1000 kg. At the rated speed of the engine, which is 750 rev/min, the engineers experienced large vibrations of the floor. It has been decided to reduce these vibrations by suspending a spring-mass system at the bottom surface of the floor as the absorber. (a) If the stiffness of the absorber is 980 kN/m, find the mass of the dynamic absorber to be attached to the floor. (b) Find the values of the absorber mass and absorber stiffness in order to have the natural frequencies of the combined system at least 25% away from the forcing frequency. Verify your answer with a calculation.

A reciprocating engine is installed on the fifth floor of a new building to provide ventilation services, which can be modelled as a rigid rectangular plate resting on four elastic columns. The total mass of the engine and floor is 1000 kg. At the rated speed of the engine, which is 750 rev/min, the engineers experienced large vibrations of the floor. It has been decided to reduce these vibrations by suspending a spring-mass system at the bottom surface of the floor as the absorber. (a) If the stiffness of the absorber is 980 kN/m, find the mass of the dynamic absorber to be attached to the floor. (b) Find the values of the absorber mass and absorber stiffness in order to have the natural frequencies of the combined system at least 25% away from the forcing frequency. Verify your answer with a calculation.

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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