Influence of Relative Humidity on the Thermomechanical Behavior of PA6.6

An experimental protocol was developed to achieve complete energy balances associated with low cycle fatigue (LCF) of a polyamide 6.6 matrix (PA6.6). The protocol involves quantitative infrared techniques (IRT), and digital speckle image correlation (DIC). IRT data were used with a local heat diffusion equation to estimate strain-induced heat sources, namely dissipation and coupling sources, while DIC enabled strain and stress assessments. Both techniques were then successfully combined to quantify deformation, dissipated and stored energies and then to estimate the Taylor-Quinney ratio that is widely used in plasticity.