A rotor-shaft system (Figure P4.8) consisting of torsional stiffness \(k_{1}\) and mass-moment of inertia \(J_{1}\) is subjected to a sinusoidal torque with magnitude \(1.3 \mathrm{kN}\)-meter. When the excitation frequency equals \(80 \mathrm{~Hz}\), there is a large amount of vibration.

Figure P4.8 

Design an undamped vibration absorber with the requirement that the system will be safe for \(20 \%\) fluctuation in excitation frequency around \(80 \mathrm{~Hz}\). Determine the amplitude of the absorber rotor \(J_{2}\) at \(80 \mathrm{~Hz}\).

Transcribed Image Text:

k1 J1 k2 J2 Torque Vibration absorber