Questions & Answers of Vibration Isolation

Weightage of Vibration Isolation

Total 3 Questions have been asked from Vibration Isolation topic of Vibrations subject in previous GATE papers. Average marks 1.67.

A machine of mass $ m=200 $ kg is supported on two mounts, each of stiffness $ k=10 $ kN/m. The machine is subjected to an external force (in N) $ F\left(t\right)=50\;\cos\;5t $. Assuming only vertical translatory motion, the magnitude of the dynamic force (in N) transmitted from each mount to the ground is ______ (correct to two decimal places).

 

A precision instrument package(= 1 kg) needs to be mounted on a surface vibrating at 60 Hz. It is desired that only 5% of the base surface vibration amplitude be transmitted to the instrument .Assume that the isolation is designed with its natural frequency significantly lesser than 60 Hz, so that the effect of damping may be ignored. The stiffness (in N/m) of the required mounting pad is ________.

In vibration isolation, which one of the following statements is NOT correct regarding Transmissibility (T)?