TABLE OF CONTENTS The first part of this chapter is devoted to various types of shock and vibration isolators, as well as their characteristics. The next topic considered is the properties of combinations of isolators in series and in parallel. A discussion is presented on the selection, installation, and specification of isolators. Then consideration is given to isolators that are combined with masses and damping, forming a vibration control system that can, for example, permit equipment to function as intended, often lengthening its operable life; protect sensitive equipment mounted on a structure from damage as a result of shock and vibration occurring in the structure; and reduce the level of noise and vibration near the equipment, or provide greater comfort to nearby occupants of a building.
The last section of this chapter considers the principles of active vibration control systems that differ from passive (conventional) control systems, described earlier, in that they supply additional power (controlled by one or more sensors) that is fed into the system so as to modify its behavior. In many special cases, this additional complication is worthwhile in that it can provide the system with benefits not otherwise obtainable.
Isolators are commercially available in many different resilient materials, in countless shapes and sizes, and with widely diverse characteristics. In the U.S.A. there are well over 100 elastomeric isolator manufacturers, each offering a range of models in a variety of synthetic elastomeric compounds and natural rubbers.
