Damping properties of syntactic foams with nanoparticulate additives

Polymer-based damping materials can be filled with microballoons to create closed cell syntactic foams. As well as having an ability to dissipate vibration energy, syntactic foams are light and relatively strong. For this reason they make excellent damping materials when used as fillers in hollow cavities. It is shown that to damp vibration in hollow cavities, the foam needs to have a modulus that is significantly higher than that seen in common damping materials. While it is desirable to combine low density with high modulus and damping over a broad temperature range, it is rarely achievable with traditional syntactic foams. This paper reports work carried out to modify the properties of syntactic foams through the addition of nanoparticulates to the mix. It has been claimed that by reducing the average particle size from micro-scale to nano-scale, dramatic increases in stiffness and damping capability can be achieved. Modifications in the properties of syntactic foams that can be achieved using nanoparticulates are investigated experimentally Results are reported for both silica nanoparticulates and carbon nanofibres. The effect of these changes on the vibration properties of two different example structures are demonstrated numerically.