title: Discontinuous Buckling of Wide Beams and Metabeams.
abstract: We uncover how nonlinearities dramatically alter the buckling of elastic beams. First, we show experimentally that sufficiently wide ordinary elastic beams and specifically designed metabeams-beams made from a mechanical metamaterial-exhibit discontinuous buckling, an unstable form of buckling where the postbuckling stiffness is negative. Then we use simulations to uncover the crucial role of nonlinearities, and show that beams made from increasingly nonlinear materials exhibit an increasingly negative postbuckling slope. Finally, we demonstrate that for sufficiently strong nonlinearity, we can observe discontinuous buckling for metabeams as slender as 1% numerically and 5% experimentally.
authors.affiliation: Huygens-Kamerlingh Onnes Lab, Universiteit Leiden, P.O. box 9504, 2300 RA Leiden, The Netherlands.|FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Corentin
authors.initials: C
authors.lastname: Coulais
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Johannes T B
authors.initials: JT
authors.lastname: Overvelde
authors.affiliation: Huygens-Kamerlingh Onnes Lab, Universiteit Leiden, P.O. box 9504, 2300 RA Leiden, The Netherlands.|FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Luuk A
authors.initials: LA
authors.lastname: Lubbers
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Katia
authors.initials: K
authors.lastname: Bertoldi
authors.affiliation: Huygens-Kamerlingh Onnes Lab, Universiteit Leiden, P.O. box 9504, 2300 RA Leiden, The Netherlands.|FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: van Hecke