Damping Applications with Machines

The machine augmented composite concept has also been extended to act as a new type of structural damping material. Embedded in the material are many fluid-filled machines that absorb the energy of vibrations. The material can be designed for use in low-frequency applications such as structural damping of buildings or bridges. Alternatively, the material may also be designed to damp higher frequencies such as those found in launch vehicles, airplanes, and automobiles.

Finite element model used to design machine shape for most effective applied strain-to-volume decrease optimization.

This graph shows the effect of applied compressive strain on the cross-sectional fluid-filled area for the hour glass extruded machines. This effect translates into very small applied external strain having a large effect on the pumping efficiency of the machine.

Dynamic mechanical analysis of machine augmented composites under compressive load frequency sweeps. Samples can be tested from 0.1 to 200 Hz through a temperature range from -120 degrees to 200 degrees.

Current studies are focusing on the effects of the viscosity, machine shape, and volume percent ratio. Experiments are being performed on materials tested in a dynamic mechanical analyzer as show. Samples have been tested at frequencies from 0.1 Hz to 200 Hz.