Experimental characterization and modelization of the relaxation and complex moduli of a flexible adhesive

In this paper, the experimental characterization and modelization of the relaxation and complex moduli of the flexible adhesive ISR 70-03 by means of dynamic mechanical thermal analysis technique (DMTA) is presented. Firstly, the procedure followed to obtain and to validate the test specimens is described. Next, the linearity concerning material behavior related to strain level and test specimen thickness is analyzed. Then, relaxation and dynamic master curves under tension strain are built-up by means of a procedure based on the time–temperature superposition principle. Finally, these master curves are modelized using a generalized Maxwell model and a fractional derivative model. As a result, models capable of taking together into account the influence of time, temperature and strain level are proposed.

Research highlights
► A generalized Maxwell model and a fractional derivative model have been fitted.
► The influence of time, temperature and strain level are modelized.
► A procedure based on the TTS principle has been applied to obtain E(t  ) and E∗(ω)E∗(ω).
► The temperature dependence has been modelized by an Arrhenius model.
► A linearity analysis on sample thickness and on strain influence has been carried out.