Broadband vibration analysis of the periodically stitched sandwich structure

This work presents a numerical study on the broadband vibration analysis of periodically stitched sandwich structures. Firstly, a finite element model is established for the unit cell, which is capable of taking into account different layers of the sandwich as well as the stitches. The wave propagation properties in different frequency bands are analyzed by applying the Floquet-Bloch theorem to the boundaries of the unit cell. Then, the influences of structural design parameters on broadband dynamic responses are discussed. Simulation results indicate that the dynamic response of the investigated stitched sandwich structure is mainly determined by various far-field propagating waves. Structural dynamic response in the medium and high frequency ranges is significantly suppressed by introducing stitches into the sandwich structure. A more intensive stitch density, larger stitch diameter, and thicker core layer could make the resonance peaks of structural displacement response shift towards lower frequency, which is more obvious in the medium and high frequency bands.