Print Email Facebook Twitter Strain rate-dependent mechanical metamaterials Title Strain rate-dependent mechanical metamaterials Author Janbaz, S. (TU Delft Biomaterials & Tissue Biomechanics) Narooei, K. (K.N. Toosi University of Technology) van Manen, T. (TU Delft Biomaterials & Tissue Biomechanics) Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics) Date 2020 Abstract Mechanical metamaterials are usually designed to exhibit novel properties and functionalities that are rare or even unprecedented. What is common among most previous designs is the quasi-static nature of their mechanical behavior. Here, we introduce a previously unidentified class of strain rate-dependent mechanical metamaterials. The principal idea is to laterally attach two beams with very different levels of strain rate-dependencies to make them act as a single bi-beam. We use an analytical model and multiple computational models to explore the instability modes of such a bi-beam construct, demonstrating how different combinations of hyperelastic and viscoelastic properties of both beams, as well as purposefully introduced geometric imperfections, could be used to create robust and highly predictable strain rate-dependent behaviors of bi-beams. We then use the bi-beams to design and experimentally realize lattice structures with unique strain rate-dependent properties including switching between auxetic and conventional behaviors and negative viscoelasticity. To reference this document use: http://resolver.tudelft.nl/uuid:15fafdf7-0281-43c7-9db9-2bb6e974a3ac DOI https://doi.org/10.1126/sciadv.aba0616 ISSN 2375-2548 Source Science Advances, 6 (25) Part of collection Institutional Repository Document type journal article Rights © 2020 S. Janbaz, K. Narooei, T. van Manen, A.A. Zadpoor Files PDF eaba0616.full.pdf 1.62 MB Close viewer /islandora/object/uuid:15fafdf7-0281-43c7-9db9-2bb6e974a3ac/datastream/OBJ/view