Vibration normally becomes a problem for one of two reasons; either the amplitude of the vibration is large enough to cause excessive stress, or it is large enough to disturb the people in, on or near the vibrating object(s). As far as most structures are concerned, vibration will disturb (or scare!) the people around the structure long before stress becomes a problem. Additionally, there are many items of equipment (balances, scanning electron microscopes, step and repeat cameras etc.) that are even more sensitive than people to vibration .
Dynamic Analysis has pioneered many of the measurement and analysis techniques necessary to predict and alleviate structural vibration problems. We have used analytical models (typically using Finite Element techniques) to determine the dynamic response of structures ranging from small individual components to entire buildings. In one such study, we determined in the design stage the modifications required to limit train-induced vibrations on an upper floor of a new concrete structure. This process included defining the vibration sensitivity of the equipment to be installed, measuring the train-induced vibration levels and soil conditions at the building site and constructing an analytical model of the proposed structure and soil system.