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arXiv · 2208.14278

Snap buckling of bistable beams under combined mechanical and magnetic loading

Arefeh Abbasi·Tomohiko G. Sano·Dong Yan·Pedro M. Reis
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Abstract

We investigate the mechanics of bistable, hard-magnetic, elastic beams, combining experiments, finite element modeling (FEM), and a reduced-order theory. The beam is made of a hard magneto-rheological elastomer, comprising two segments with antiparallel magnetization along the centerline, and is set into a bistable curved configuration by imposing an end-to-end shortening. Reversible snapping is possible between these two stable states. First, we experimentally characterize the critical field strength for the onset of snapping, at different levels of end-to-end shortening. Second, we perform 3D FEM simulations using the Riks method to analyze high-order deformation modes during snapping. Third, we develop a reduced-order centerline-based beam theory to rationalize the observed magneto-elastic response. The theory and simulations are validated against experiments, with an excellent quantitative agreement. Finally, we consider the case of combined magnetic and mechanical-indentation loading, examining how the applied field affects the bistability and quantifying the maximum load-bearing capacity. Our work provides a set of predictive tools for the rational design of one-dimensional, bistable, magneto-elastic structural elements.

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Arefeh Abbasi, Tomohiko G. Sano, Dong Yan, Pedro M. Reis. 2022-08-30. Snap buckling of bistable beams under combined mechanical and magnetic loading. https://doi.org/10.1098/rsta.2022.0029

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