MAE Speaker Series Seminar on Instability of elastic structures for the design of architected materials

Professor Davide Bigoni

University of Trento, Italy

This seminar will be chaired by Prof K Jimmy Hsia.

Flutter instability induced by follower loads was experimentally demonstrated with the development of the freely rotating wheel structure by Bigoni and Noselli, the flutter machine, and a dedicated device for generating Reut-type loads. Further research in this field has proven that flutter instability, Hopf bifurcation, dissipation instabilities, and Ziegler paradox are all possible in conservative systems, thus disproving an erroneous belief that has continued for at least 50 years. A new type of flutter instability is shown to be generated by the 'fusion' of two structures which are separately stable, but become unstable when joined together and so involving a discontinuity in curvature. Finally, it is shown how rigorous homogenization theory leads to the use of the above-mentioned structures to design architected materials capable of innovative mechanical properties, such as for instance the restabilization after shear banding and the possibility of achieving an elastic material violating hyperelasticity.