Tuesday  |  Heritage E  |  09:40 AM–10:00 AM

#17743, Payne Effect in Rate-Independent Soft Fibrous Materials and its Consequences

Sublinear softening in the constitutive dynamic stress-strain response, observed as a function of strain amplitude—a phenomenon known as the Payne effect—is commonly seen in various soft particulate composites and fibrous materials. The Payne effect leads to a decrease in the dynamic modulus and an increase in the loss tangent, allowing for reduced force transmission and higher energy dissipation, respectively, at large strain amplitudes, making this effect valuable for vibration mitigation purposes. Understanding the fundamental origins of the Payne effect will enable the creation of artificial structured materials with tailored energy dissipation properties. In this study, we formulate a Triboelastic frictional damping-based model. This model comprises elastic springs and friction elements, effectively capturing rate-independent damping in vertically aligned carbon nanotube (VACNT) foams and explaining the origin of the Payne effect. Our model suggests that the Payne effect arises due to the sequential unlocking of frictional elements connected in series. This sequential unlocking resembles zipping and unzipping type frictional interactions between nanotubes during the compression and decompression of VACNT foams. With our model, we anticipate enhanced predictive capabilities when utilizing soft-filled rubbers and fibrous materials like VACNT foams for energy-absorbing applications.

Abhishek Gupta   University of Wisconsin-Madison
Bhanugoban Maheswaran   University of Wisconsin-Madison
Komal Chawla   University of Wisconsin-Madison
Ramathasan Thevamaran   University of Wisconsin-Madison