噪声控制-如何理解降噪减震.pdf

Understanding Damping Techniques for Noise and Vibration Control By Jennifer Renninger Applications Engineer E-A-R Specialty Composites Indianapolis, Indiana Introduction only resonant motion. Forced, nonreso- Effective control of noise and vibration, nant vibration is rarely attenuated by whatever the application, usually damping, although application of requires several techniques, each of damping materials sometimes has that which contributes to a quieter environ- effect because it increases the stiffness ment. For most applications, noise and and mass of a system. vibration can be controlled using four A damping treatment consists of any methods: (1) absorption (2) use of material (or combination of materials) barriers and enclosures (3) structural applied to a component to increase its damping and (4) vibration isolation. ability to dissipate mechanical energy. Although there is a certain degree of It is most often useful when applied to overlap in these classes, each method a structure that is forced to vibrate at may yield a significant reduction in or near its natural (resonant) frequen- vibration and noise by proper analysis cies, is acted on by forces made up of of the problem and application of the many frequency components, is subject technique. The principles behind the use to impacts or other transient fo