Utilization of the Dynamic Mechanical Properties of Rubber-Like Materials in Vibration Control

Abstract

Literature concerned with the problems of vibration control frequently disregards the importance and value of considering the frequency dependence of the elastic modulus and the damping factor of rubber-like materials. Such a consideration has been found valuable in the following ways. Firstly, it enables criteria which define a good antivibration mount material to be determined. Secondly, it shows that a dynamic absorber utilizing a material with a stiffness proportional to frequency and a constant damping factor can reduce the resonant vibration of machinery and mounted equipment considerably. Its performance is superior to that of the classical dynamic absorber where the absorber mass is attached to the mounted item with a spring. Thirdly, it indicates that a mounting composed of natural and a high damping synthetic rubber in parallel can suppress resonant foundation motion nearly as effectively as a mount of the high damping rubber alone, yet offer much greater isolation at intervening frequencies. (This research was supported in part by the Bureau of Ships and the Office of Naval Research.)