Kirigami art and geometric manipulation transform rigid solids to flexible auxetic materials
- PDF / 604,535 Bytes
- 1 Pages / 585 x 783 pts Page_size
- 20 Downloads / 187 Views
ture opened and closed. To get around this problem, the ligament geometry was tailored in order to smooth stress peaks localized in the ligaments. Performance, bistability, and durability of the rigid BAMs were assessed, and the experiments confirmed the numerical simulations. To study bistability and failure conditions, nonlinear numerical analyses were performed on models pulled uniaxially until full expansion. BAM unit-cell samples were also tested under large displacement control using a Bose ElectroForce tester. “We can open and close the structure this monolithic architected material has been shaped into for at least 10,000 times and the functionality is preserved,” Pasini says. “This is a record-breaking resistance to fracture, in lattices undergoing such large local deformations!” says Chiara Daraio, professor of aeronautics and applied physics at the California Institute of Technology. Daraio believes that the work presented by Pasini and his team makes a leap forward in the possible application of mechanical metamaterials in engineering systems. “The authors showed a clever and elegant design strategy, to ensure the durability of bistable lattices in response to repeated loading, by using optimized ligaments for the connection of different geometrical units,” she adds. Dennis Kochmann, professor of mechanics and materials at ETH Zürich, thinks that the link established between phase transformations in materials and the periodic unit-cell design in this metamaterial is intriguing. “This new structural design paradigm exploits the smart combination of stiff elements and compliant connectors to achieve what is a rare find among natural materials: large, reversible deformation,” he says, adding that “the computational exploration of the design space highlights how the same approach can be utilized to devise a wide range of material behavior at the structural, metamaterial level.” Having as a starting point the same design approach, the team is now planning to explore whether bistabillity and auxeticity can be combined in fragile, brittle metamaterials made of glass. Eva Karatairi
• Cambridge • FEBRUARY • www.mrs.org/bulletin MRSsubject BULLETIN VOLUME 43 Core Downloaded from https://www.cambridge.org/core. Access paid by the UCSB Libraries, on 10 Mar 2018 at 04:49:50, to the terms 2018 of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/mrs.2018.12
79
Data Loading...
