Numerical and experimental investigations of wave propagation in Kelvin Cell-based periodic lattice architectures

This contribution addresses elastic waveguiding properties of 1D-periodic lattice microstructures derived from the Kelvin cell. The Kelvin cell serves as a lattice template to subsequently introduce microstructural changes by imposing twists on the cell's square faces. Such modifications break the cell mirror symmetries and offer the possibility to adjust the wave filtering characteristics based on the twist angle and choice of tesselation. Band structure analyses reveal that altering the template geometry enforces frequency gaps stemming from coupled longitudinal-torsional modes and Bragg scattering. To validate the applicability of Kelvin cell lattice structures for vibration control, finite-size samples are manufactured from SLA-printing and tested in terms of transmission spectra. The experimentally observed frequency regions of reduced transmission correspond well with the band gap layout. Simulations of finite-size samples show that visco-elastic and frequency-dependent material behavior must be accounted for to numerically predict the measured transmission characteristics.