A novel cylindrical negative stiffness structure for shock isolation

The negative stiffness (NS) metamaterial is a promising material that has attracted a great amount of interest. Many types of NS structures have been proposed and investigated. However, almost all of the previously proposed structures were cuboidal, which is undesirable for certain special engineering applications. In this paper, a cylindrical NS structure composed of spatial curved beams is proposed, and can potentially be applied to shock isolation, vibration control, and deployable structures. Specimens were fabricated using Fused Deposition Modeling (FDM) technology. The influence of the structural parameters on the NS property was investigated, and the criteria for the structure to achieve snap-through behavior were obtained. Impact tests were performed to investigate the structure's cushion performance. The results of the impact tests revealed that the structure achieved good cushion performance by thresholding the magnitude of the acceleration response, when the snap-through behavior occurred.