Dynamic Mechanical Compliance Testing
The NanoTest dynamic compliance testing module can be thought as a nanoscale analogue of dynamic mechanical analysis (DMA). After collecting the raw phase angle data with spherical or pyramidal indenters, it is analysed with a 4-element linear viscoelastic model to determine loss and storage modulus, indentation complex modulus and tan delta which are indicative of energy damping in the surface/near surface of the material. The example below shows an excellent fit of the model to experimental data on an epoxy sample. A value for tan delta of 0.017 was determined in good agreement with bulk DMA values.
Variation in phase signal with indentation depth for three repeat tests on an epoxy sample. The reproducibility of the data and its fit to the 4-element linear viscoelastic model used in the analysis is good and produces a value of tan delta of 0.017.
Further Reading
Displacement Modulation Based Dynamic Nanoindentation for Viscoelastic Material Characterization, SP Singh, RP Singh, JF Smith, Mater. Res. Soc. Symp. Proc. Vol. 841 (2005) R4.6
Characterization of the Damping Behavior of a Nanoindentation Instrument for Carrying Out Dynamic Experiments, SP Singh, JF Smith, RP Singh, J Mater. Res. Vol 21 No. 6 (Jun 06) 1576-1589
