Question

A motor is mounted on a platform that is observed to vibrate excessively at an operating speed of 6000 rpm producing a 250-N force. Design a vibration absorber (undamped) to add to the platform. Note that in this case the absorber mass will only be allowed to move 2 mm because of geometric and size constraints.

Answer 1

The amplitude of the absorbed mass can be found

for ka:

`X_(a) =0.002m=(F_(0) )/(K_(a) ) =(250)/(K_(a) ) =125000N/m`

now

`w^2=(K_(a) )/(m_(a) ) \\m_(a) =(K_(a) )/(w^2) =(125000)/([6000*2\pi /60]^2) =0.317kg`