Absorption characteristics of particulate dampers to mitigate structural vibration Hasson M. Tavossi, Ph.D., Savannah State University, Department of Engineering Technology, 3219 College St., Savannah, GA 31404.

Interior and exterior structural vibrations can be efficiently damped by particulate materials. The absorption spectral characteristics of the material depend on the particulate mechanical properties, their shapes, size distribution, and degree of consolidation. Experiment show that unconsolidated particulate dampers acts as a band-pass filter for vibration frequencies that is transmitted through them. The particulate materials can also have spectral frequency band-gap structure where a band of frequency of mechanical vibrations is strongly attenuated; by absorption, scattering, or localization of vibration energy. In this investigation samples of unconsolidated uniform size spherical particulates are subjected to forced mechanical vibration at different frequencies and amplitudes, to determine their absorption characteristics as a function of frequency and direction of propagation. The effects of particulate size and thickness layer are considered, in the frequency ranges encountered in building vibrations. The goal of this investigation is to find the required characteristics for particulate dampers for absorption of building vibrations.