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Directional Delamination of Elastic Ellipsoidal Shells

Hamid Ebrahimi (Northeastern University), Amin Ajdari (Northwestern University), Arezki Boudaoud (), Dominic Vella (University of Oxford), Ashkan Vaziri ()

Soft Materials and Structures

Tue 10:45 - 12:15

Barus-Holley 158

Complicated structural features at a much smaller scale than overall structure size, form in deformation of elastic shells under mechanical loading. These features, which can be seen by simple experiments in everyday life as well as in biological and engineering systems, are associated with high energy density, and evolve in intricate ways as the shell is further loaded deep into the nonlinear regime. The key challenge in understanding these features is intraction of physics and geometry that leads to a mechanical response which is a lot different from the response of solid objects. The quest to the underlying phenomena has spawned theoretical and experimental studies, which have helped in understanding the mechanisms of deformation and response of shells. In this work, we perform a scaling analysis to determine onset of delamination of ellipsoidal shells with a wide range of axis ratio under indentation with a flat plate as well as amplitude and wave length of wrinkles. Detailed numerical simulations were carried out to study response of elastic shells and results are in good agreement with the theory. Several specimens were cast using a liquid silicon based elastomer, Vinylpolysiloxane, and simple experiments were done to show evolution and progress of delamination of shells. Wavelength of wrinkles that were measured from experiments were compared with numerical an theoretical results.