At the invitation of Prof. Ji Wang, Prof. Fan Yang from Tongji University visited the School of Mechanical Engineering & Mechanics, Ningbo University, on June 19, 2019. Dr. Yang gave a talk on the deformation mode and energy absorption performance of several new energy absorbers.
Energy absorbers such as thin-walled tubes are the major components of the passive vehicle safety system. The energy absorption performance of a structure is closely related to its deformation mode. It is important to make sure that the structure is crashed in a progressive deformation mode in the design of energy absorbers, especially under the oblique loading condition. In this work, a theoretical model was developed to obtain the mean crushing force and the instantaneous crushing force for the foam-filled concertina and diamond deformation modes based on the kinematically admissible mechanisms. Experiments and finite element simulations were further carried out to investigate the deformation mode and energy absorption of several new configuration of designs. Finally, feasibility of using multi-level and polycrystal-inspired macro-lattice concepts to design new energy absorbers was discussed. This study aims at providing guidance for design of new energy absorbers with higher specific energy absorption, lower initial peak crushing force, and more stable deformation mode.
Dr. Fan Yang is an Associate Professor at Tongji University and currently the Assistant Dean of the School of Aerospace Engineering and Applied Mechanics. He received his B.S. in Engineering Mechanics from Tsinghua University and his Ph.D in Mechanics from Tsinghua University in 2009. He worked as a Postdoctoral Researcher respectively in the Ohio State University and University of Toronto from 2019 to 2014. Then he started to work in Tongji University from 2014. His research interests include fracture behavior of nanocrystalline metals, energy absorption of thin-walled structures, thermal stress analysis of electronics, ultrathin polymer films, and so on. He has published more than 30 papers in peer-reviewed international journals. He is now serving as Secretary-General of the Professional Committee on Solid Mechanics in Shanghai Society of Theoretical and Applied Mechanics, Vice Secretary-General of the Professional Committee on Surface Modification in Chinese Mechanical Engineering Society.