A novel metamaterial for tunable load-bearing and broadband vibration isolation based on combined double-helix and chiral unit cell

In the advanced high-performance mechanical systems, such as those in aerospace, automotive powertrains, and precision instrumentation, demand components that can simultaneously provide structural support and mitigate harmful vibrations. However, achieving an optimal balance between load-bearing capacity and vibration suppression remains a fundamental challenge, as these two functions often impose conflicting material and structural requirements. To address this inherent trade-off, this study proposes a novel metamaterial that integrates a DNA-inspired double-helix architecture with a spiral configuration. The static mechanical performance and dynamic transmissibility of topological variants, with strut side lengths of 2.0–2.8 mm, are systematically investigated. The results reveal a fundamental trade-off: increasing the strut thickness enhances the specific stiffness but shifts the fundamental resonant frequency from 51.65 Hz to 88.57 Hz, which significantly narrows the low-frequency isolation bandwidth. Experimental validation was conducted on a Selective Laser Sintering fabricated prototype, which confirmed the numerical predictions with a frequency deviation of less than 1.6%. Furthermore, a comparative analysis against a solid block is conducted to introduce and evaluate the concept of mass efficiency. The 2.0-mm topology achieves a substantial weight reduction of approximately 38.91% while achieving a maximum vibration attenuation of 45 dB, whereas the equivalent solid block provides negligible isolation. A Pareto optimization analysis demonstrates that the proposed spiral structure functions as a tunable platform, allowing for the customized balancing of static stability and dynamic filtering efficiency for lightweight applications.