Simultaneous measurement of elastic constants from dynamic mechanical analysis with digital image correlation

Dynamic mechanical analysis (DMA) method is used for measuring viscoelastic properties of materials. The governing equations used for calculating modulus neglect shear deflection component and use an assumption of constant Poisson's ratio in absence of methods that can conduct full field deformation measurement. The present work is focused on using an in-situ imaging method to obtain the full field displacement during the specimen deformation. Digital image correlation is used to calculate the values of Poisson's ratio over temperature and strain to implement a correction factor in the complex moduli calculations. The method developed in this work will provide accurate measurements of viscoelastic properties of polymers, especially for materials whose properties are very sensitive to Poisson's ratio values and temperature variations.