Dual-nozzle 3D printing of fiber composites for fabrication of compliant lever-type vibration isolators with wide stopband

This study proposes fiber-composite lever-type vibration isolators with a wide stopband around the antiresonance frequency. The proposed mechanisms were 3D-printed monolithic structures with compliant butterfly hinges that mimic an ideal pinned support for the lever. Continuous carbon fiber and short carbon fiber regions were combined to achieve a wide low-frequency stopband. A rigid link model was developed to derive analytical solutions for the resonance and antiresonance frequencies of the proposed mechanisms. Frequency response analysis and modal analysis were performed to examine designs for widening the stopband using the finite element method. The print path-dependent anisotropy of short fiber-reinforced plastic was reflected in the finite element model. A dual-nozzle fiber-composite 3D printer was used to fabricate the proposed lever-type mechanisms. The measured vibration transmissibilities of the 3D-printed samples showed a similar improvement of the stopband width to the numerical analysis results, demonstrating that suitable designs of continuous fiber placement and hinge shape widened the stopband.