Torsional negative stiffness mechanism by thin strips

• Main Authors: Jinyou Li, Kangjia Fu, Yongpeng Gu, Zhihua Zhao
• Format: Article
• Language: English
• Published: Elsevier 2019-05-01
• Series: Theoretical and Applied Mechanics Letters
• Online Access: http://www.sciencedirect.com/science/article/pii/S2095034919300364

ABSTRACT: Negative stiffness mechanisms have great application potential in different fields, such as vibration isolation, energy absorption and mesh antenna unfolding. Although numerous compliant mechanisms with negative stiffness features have been implemented in literature, the designing work remains in its infancy, and proposing an original design strategy may open a new avenue for the future inventions. In this study, inspired by a toy, we developed a novel type of compliant mechanism composed of thin strips, possessing negative stiffness property under torsion. The negative stiffness feature is achieved by large deformation of the strips rather than mechanical buckling. As a consequence, the obtained negative stiffness segment covers a significantly long range. Demonstrated with examples, it was shown that the proposed mechanisms could be combined with other compliant mechanisms to realize long-range unusual torque-angle relationships, which can be used in different applications. Keywords: Negative stiffness, Compliant mechanism, Strip, Torsional spring, Flexible multibody system