Design and Investigation of Mechanical Properties of Additively Manufactured Novel Coil-Shaped Wave Springs

Additive Manufacturing (AM) has revolutionized the production of intricate geometries tailored to customized functional mechanical properties, making it widely adopted across various industries, including aerospace, automotive, and biomedical sectors. However, the fabrication of mechanical springs has remained largely constrained by conventional manufacturing techniques, which limit their cross-sectional geometries to regular shapes, thereby restricting their mechanical performance and energy absorption capabilities. This limitation poses a significant challenge in applications where enhanced load-bearing capacity, energy absorption, and tailored stiffness characteristics are required. To address this issue, this study investigates the influence of coil shape on the mechanical properties of wave springs, specifically focusing on load-bearing capacity, energy absorption, stiffness, and compression behavior during cyclic loading and unloading. Nine contact-type wave springs with distinct coil shapes—square, rectangular, pentagonal, hexagonal, heptagonal, octagonal, quadro, circular (4 waves per coil), and circular (6 waves per coil)—were designed and fabricated using MultiJet Fusion (MJF) technology. Uni-axial compression testing was conducted over ten loading–unloading cycles to evaluate their mechanical performance and deformation characteristics. The results indicate that wave springs with square and rectangular coil shapes exhibit the highest energy absorption while maintaining the lowest stiffness and minimal energy loss during the first ten loading–unloading cycles. Furthermore, experimental findings were validated using finite element analysis (FEA) under identical boundary conditions, demonstrating close agreement with a deviation of only 2.3% compared with the experimental results. These results highlight AM’s potential for customizing wave springs with optimized mechanical performance.