Effects of geometry and mass distribution in 3D printed metastructures for vibration mitigation

Abstract

This presentation will discuss our recent progress on mechanical metastructures, which have engineered micro- and meso-scale features and are designed to have prescribed vibration mitigation properties. The goal of this work is to understand how the geometry and structure of a material can manipulate elastic wave propagation. Specifically, we developed a class of 3D printed metastructures that support low and wide band gaps, by combining periodic lattices with embedded resonant inclusions. The band gaps in these metastructures have significant shifts in frequency with small geometry changes in the unit cell design. We use finite element method simulations to calculate how band gaps in infinitely periodic metastructures depend on how the material is distributed throughout the unit cell. We study different lattice geometries that exhibit a variety of bend- and stretch-dominated deformations, as well as different volume fraction and placement of resonant inclusions. We fabricate metastructures with 3D printing and measure their frequency-dependent vibration transmission to experimentally validate their behavior. These metastructures have engineering applications in structural components that prevent the propagation of damaging structural vibrations.