Question

An exhaust fan, of weight 750 N and operating speed 60 kHz, produces a repeating force of 10,000 N on its rigid base. If the maximum force transmitted to the base is to be limited to 2000 N using a damped isolator with damping ratio of 0.1, determine

1. the maximum permissible stiffness of the isolator that meets the requirement;
2. the steady-state amplitude of the exhaust fan with the isolator that has the maximum permissible stiffness; and
3. the maximum amplitude of the exhaust fan with isolation during start-up.

Answer 1