Double-arc beam-based programmable multistable mechanical metamaterials with energy-absorbing properties

Abstract Multistable mechanical metamaterials capable of multiple stable states show great potential for energy absorption and vibration isolation. However, in conventional multistable metamaterials, the repetitive configuration of similar bistable beam units often leads to unpredictable snapping sequences between stable states. To control energy absorption and snapping sequence, a layered multistable metamaterial with programmable deformation via selective hollowing is proposed. Inspired by variable cross-section beams, a novel in-plane double-arc beam structure (DABS) with bistability and enhanced specific energy absorption ( E SA ) is developed. Its mechanical properties and energy absorption mechanisms are examined through simulations and experiments at both the unit cell and planar array levels. Results show that the peak and valley forces of the DABS are highly sensitive to the thickness-to-span and height-to-span ratios. Compared with the filled DABS unit, the hollowed unit with selective perforation improves E SA by approximately 19.1%. Furthermore, layered cylindrical metamaterials are constructed using convolutional and arrayed configurations. These metamaterials demonstrate clearly defined snap-through sequences and outstanding energy absorption performance under quasi-static compression and impact tests. Notably, the snap-through sequence in the multilayer cylindrical structures can be programmed by strategically arranging the hollowed units. This work provides new possibilities for structural design and applications of multistable metamaterials.