Damping, Mountings and Vibration

Vibration gives rise to two main types of design problems: one is that of isolating a body from random external inputs, the other, mounting a vibrating system so that as little vibration as possible is transmitted. The first is the transport (passenger or delicate cargo) problem; the second is the general machine or engine-mounting problem. A subsidiary problem is predicting and stopping odd component resonances. For the first case, particularly considering human cargo, there are some agreed standards of what inputs a person can accept for various lengths of time without undue fatigue. Unfortunately there are two sets of data in existence, sometimes confused with each other, one referring to drivers and passengers in vehicles, the other to people in buildings who have to stand, sit on relatively firm chairs or work on rigid tables. An internationally agreed set of standards for tolerable accelerations is given in Neale50, section D3, but specific body resonances are not included.