A novel flexural lamina emergent spatial joint

Origami and lamina emergent compliant hinges offer favorable potential applications for large-stroke compliant mechanisms. However, due to coupling problems and nonlinear deformation of the spatial beams, most lamina emergent compliant hinges should not be flexible in more than one direction. Thus, spatially compliant mechanisms are usually in the form of complex three-dimensional structures, which are difficult to miniaturize. In this paper, we present a flexural Lamina Emergent Spatial (LES) joint that can decompose large spatial rotations by employing the combination of a Out-of-plane Rotational Part(ORP) and a In-plane Rotational Part(IRP). First, the geometric model of the LES joint is established. Second, a closed-form expression for the compliance matrix of the initial configuration is derived for normalized analysis of the compliance ratios. Third, the relationship between the beam aspect ratios and compliance ratios is analyzed to obtain the overall normalized planar structure of the LES joint. Finally, a detailed analysis is performed to compare the optimized results with that of the finite element analysis, and the feasibility of the LES joint is verified by practical application prototypes. (C) 2019 Elsevier Ltd. All rights reserved.