报告人：张腾(Teng Zhang) 教授 Department of Mechanical and Aerospace Engineering, Syracuse University 美国 雪城大学
Thin elastic sheets floating on water surface can undergo complicated instabilities, which are determined by the nonlinear interplay of bending energy, gravity, surface energy, and external loading. Understanding these patterns will not only advance our knowledge of the fundamental physics and mechanics of thin sheets but also have great practical interests in designing multifunctional devices by harnessing these patterns. In this talk, I will describe our recent progress on wrinkling, crumpling, and folding in elastic thin sheets through two typical set-ups (1) annular sheets with different surface tension at the inner and outer boundaries and (2) circle sheets under poke. For the annular wrinkling, we uncover the coupling effect of gravity and surface tension on the wrinkle number and profiles through generalizing a universal scaling law for thin sheet wavelength and performing large-scale finite element simulations. I will then discuss the study of poking a floating circle sheet, with a focus on how these geometry nonlinear deformations will alter the resultant force in response to the poke. Our simulations capture the 4 nonlinear deformation regimes predicted by theoretical analysis and also are in good agreement with experiments conducted by our collaborators.
Dr. Teng Zhang is an Assistant professor in the Department of Mechanical and Aerospace Engineering at Syracuse University. Prior to Joining Syracuse, he was a Postdoctoral associate in the Department of Mechanical Engineering at MIT and received his PhD degree at Brown University in 2015. He received his Bachelor (2007) and Master (2010) degrees at Dalian University of Technology, China. His group is dedicated to applying mechanics modeling and simulation to design advanced materials and structures for improving our daily life, from novel 2D materials for clean water to stretchable and tough soft materials for bio-medical structures and devices, from shape changing pasta to wrinkling patterns in various biological and engineering structures. Dr. Zhang has received the NSF Faculty Early Career Development Award to support his research on the fundamental mechanics of interfaces in soft materials. He has published more than 30 research papers in high impact journals, including Nature Materials, Nature Communication, Physical Review X, Advanced Materials, and Journal of Mechanics and Physics.