JNNFM-JOR-RA seminar series

Title：Elasticity and Damping of Viscoelastic Solids

Lecturer: Professor H. Henning Winter, University of Massachusetts Amherst (USA)

Time: 15 November 2023, 18:00 CET，12noon EST / 24:00 CST or 0:00 CST 北京时间，11月16日 凌晨

Join the webinar - https://us06web.zoom.us/j/86712970115?pwd=U3JEbzRJbkhqL0N2RTZOanYxVmpqQT09  

Meeting ID: 867 1297 0115; Passcode: 727715

ABSTRACT：

Viscoelastic materials combine both elastic (spring-like) and viscous (fluid-like) properties, allowing them to store and gradually dissipate mechanical energy and dampen external energy. This dual nature is valuable in applications th at require both energy storage and dissipation. Bonding objects with viscoelastic adhesives is a notable example where this dual nature is significant, as such adhesives can form robust bonds while also dampening by dissipating energy. This damping ability is advantageous in scenarios where you aim to reduce vibrations, absorb shocks, or dampen noise, as common in buildings, cars, ships, and machinery in general.

In this talk, we will examine the underlying rheological properties that can accelerate the discovery and development of materials where both elastic connectivity and energy dissipation are critical for performance and safety. This presentation primarily investigates the possibilities and limitations of applying the Deborah number concept to solids, although mostly the same analysis would apply to viscoelastic liquids (however, with G0 =0), The focus here is primarily on the less-explored field of solids. Of particular interest is the balance of elasticity and damping, with a focus on gels and gelation as examples. Time-resolved rheometry tools of IRIS Rheo-Hub will be employed to explore these concepts. For gelation, the Deborah number (De) diverges at the gel point and decreases thereafter, as shown in the figure, while damping decays as the reciprocal of the damping parameter (1/Rd) increases beyond the gel point.