TY - JOUR
T1 - Design strategy of curved-beam based metamaterial with unprecedented lateral deformation mode transition
AU - Ji, Jinyu
AU - Zhang, Kai
AU - Guo, Xiaogang
AU - Fang, Daining
N1 - Publisher Copyright:
© 2025
PY - 2025/4/15
Y1 - 2025/4/15
N2 - Mechanical metamaterials exhibiting unconventional Poisson's ratios hold significant promise for applications in flexible electronics, impact protection, medical devices, and shape-shifting structures. However, achieving complex Poisson's ratio behaviors—particularly nonlinear and directional-switching responses under large deformations—remains a considerable challenge. This study introduces a class of variable-thickness curved-beam metamaterials (VCBMs) capable of exhibiting intricate nonlinear lateral displacement responses, including direction-reversing behaviors, under large tensile strains. To enable the customizable design of VCBM unit cells with complex Poisson's ratio profiles, an inverse design framework integrating neural networks (NN) and particle swarm optimization (PSO) is proposed. This framework facilitates the precise tailoring of VCBM unit cells with nonlinear, sign-switching force-lateral displacement curves and enables the development of spatially heterogeneous metamaterials with unprecedented lateral deformation transitions. As a case study, the framework is applied to create metamaterials that transition from a flat configuration to a dumbbell shape and subsequently to a vase-like form under uniaxial stretching. Both numerical simulations and experimental validations confirm the effectiveness of this approach, highlighting the unprecedented lateral displacement mode transitions under tensile loading. The proposed methodology lays the foundation for developing advanced reconfigurable metamaterials with versatile applications in mechanical systems, soft robotics, programmable materials, and medical devices.
AB - Mechanical metamaterials exhibiting unconventional Poisson's ratios hold significant promise for applications in flexible electronics, impact protection, medical devices, and shape-shifting structures. However, achieving complex Poisson's ratio behaviors—particularly nonlinear and directional-switching responses under large deformations—remains a considerable challenge. This study introduces a class of variable-thickness curved-beam metamaterials (VCBMs) capable of exhibiting intricate nonlinear lateral displacement responses, including direction-reversing behaviors, under large tensile strains. To enable the customizable design of VCBM unit cells with complex Poisson's ratio profiles, an inverse design framework integrating neural networks (NN) and particle swarm optimization (PSO) is proposed. This framework facilitates the precise tailoring of VCBM unit cells with nonlinear, sign-switching force-lateral displacement curves and enables the development of spatially heterogeneous metamaterials with unprecedented lateral deformation transitions. As a case study, the framework is applied to create metamaterials that transition from a flat configuration to a dumbbell shape and subsequently to a vase-like form under uniaxial stretching. Both numerical simulations and experimental validations confirm the effectiveness of this approach, highlighting the unprecedented lateral displacement mode transitions under tensile loading. The proposed methodology lays the foundation for developing advanced reconfigurable metamaterials with versatile applications in mechanical systems, soft robotics, programmable materials, and medical devices.
KW - Curved beam
KW - Deformation mode transition
KW - Inverse design
KW - Poisson's ratio
KW - Variable thickness
KW - VCBMs
UR - http://www.scopus.com/inward/record.url?scp=105000241871&partnerID=8YFLogxK
U2 - 10.1016/j.ijmecsci.2025.110136
DO - 10.1016/j.ijmecsci.2025.110136
M3 - Article
AN - SCOPUS:105000241871
SN - 0020-7403
VL - 291-292
JO - International Journal of Mechanical Sciences
JF - International Journal of Mechanical Sciences
M1 - 110136
ER -