Dynamic Mechanical Compliance Testing
The NanoTest dynamic compliance testing module can be thought as a nanoscale analogue of dynamic mechanical analysis (DMA) [4]. 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.
Fig 1: 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.
