Particle Tuned Mass Dampers: Design, Test, and Modeling

Abstract

The objective of this research is to design, build, and test a particle tuned mass damper (PTMD) and to develop prediction capabilities for particle dampers in both 1g and zero-g environments through experiment and computer simulation. The applications of this technology are quite diverse because particle dampers are inexpensive to build, may be adapted to accommodate almost any geometry, and are unaffected by environmental changes, specifically temperature, which has a dramatic effect on the performance of the visco-elastic materials often used for vibration isolation and attenuation. In recent years successful implementation has raised considerable interest in the applications and simulations of particle dampers. Here a modified particle system, a particle tuned mass damper (PTMD), is introduced that combines the desirable characteristics of both particle dampers and tuned mass dampers (TMD). It is known that the performance of particle dampers is not very sensitive to frequency, whereas a tuned mass damper is very sensitive to frequency and highly efficient at the tuned frequency. Thus, by combining the merits of TMDs with those of particle dampers it is anticipated that these new PTMD devises will be more robust and perform more effectively with built-in damping adjustability. An adjustable frequency PTMD was designed, fabricated, and tested. The device consists of an adjustable length cantilever beam to the end of which a particle damper is attached securely. The damper cavity is cylindrical in shape and is partially filled with particles. For tuning purposes, the distance from the top surface of the particle bed to the top of the enclosure is also adjustable. The damper will be excited with a sine sweep force using a shaker. The following parameters will be adjusted: (a) force amplitude, (b) beam length, and (c) cavi ty volume for a fixed amount of particles. The test results will be presented with in the form of transfer functions.