Design, Fabrication and Evaluation of Negative Stiffness Elements

Abstract

Recent research has shown that constrained bistable structures can display negative stiffness behavior and provide extremal vibrational and acoustical absorptive capacity. These bistable structures are therefore compelling candidates for constructing new metamaterials for noise reduction, anechoic coatings, and backing materials for broadband imaging transducers. To date, demonstrations of these capabilities have been primarily theoretical, because the geometry of bistable elements is difficult to construct and refine with conventional manufacturing methods and materials. The objective of this research is to exploit the geometric design freedoms provided by selective laser sintering (SLS) technology to design and construct constrained bistable structures with negative stiffness behavior. The static and dynamic behaviors of resulting bistable structures are experimentally investigated. Initial bistable designs and test results are presented in this paper.