THE EFFECT OF VIBRATION ISOLATOR PROPERTIES AND STRUCTURAL STIFFNESS ON ISOLATOR PERFORMANCE

The structural stiffness above and below a vibration isolation mount h as an important effect on isolator performance. Knowledge of these as well as isolator properties is necessary to be able to predict the ins ertion loss of an isolator and the transmitted power to the foundation . A set of generalized mobility equations is used to analyze both the single-connection point and multiple-connection points cases. Experime ntal methods for determining the four-pole parameters, which describe the frequency-dependent dynamic properties of a vibration isolator, ar e discussed, and the test facility developed by the authors for the me asurement of four-pole parameters is described. Test results for a com mercially available isolator are presented. The importance of the stru ctural dynamic properties above and below the isolator is illustrated by calculating the isolator effectiveness for different foundation pro perties.