Non-Invasive Experimental Investigation for Time-Temperature Superposition Shift Factor Estimation in Viscoelastic Materials Characterization

The characterization of viscoelastic materials, important for mechanical, aerospace, biomedical, and many other fields of application, poses an arduous challenge due to the great variability of their properties with both temperature and frequency. This characterization is generally performed with mechanical and destructive tests, including the Dynamic Mechanical Analysis (DMA). However, in recent times, non-invasive techniques have emerged as promising alternatives, such as the Viscoelasticity Evaluation System Evolve (VESevo) device. This work focuses on experimental investigation employing different configurations of the VESevo device to perform the characterization of polymeric material at different frequencies over a large range of temperatures. The feasibility of this approach is also supported by a prior simulation study in which the prototyping and testing of the different elements were carried out. The task of this study is to prove the possibility of generating, with the VESevo device, curves of viscoelastic material properties as a function of temperature at different testing frequencies, which are sufficiently detached to establish a shift law and to derive a complete temperature-frequency relationship. Contrary to simulations, the experimental implementation revealed no clear distinction between the curves allowing the construction of an extended master curve. However, the methodology is promising and with a more detailed analysis and a potential experimental apparatus improvement, the desired results seem achievable. If these objectives can be attained in this efficient non-destructive way, it would represent a major advancement in polymer characterization, reducing costs and characterization times, with a wide range of possible applications.