When a free-vibration test is run on the system of Figure P4.76, the ratio of amplitudes on successive cycles is 2.8 to 1 . When operating, the engine has a rotating unbalance of magnitude \(0.25 \mathrm{~kg} \cdot \mathrm{m}\). The engine operates at speeds between 500 and \(2500 \mathrm{rpm}\). For what value of \(\omega\) within the operating range will the pump's steady-state amplitude be largest? What is the maximum amplitude? Assume the damping is hysteretic.

Transcribed Image Text:

E 200 x 109 N/m I = 2.4 104 m 215 kg FIGURE P4.76 3.1 m