Woodpile Mechanical Metamaterials for Sculpting Stress Waves
Abstract
The technical objective of the proposed effort is to develop unique mechanical nonlinear metamaterials to demonstrate the ability to controllably sculpt stress waves in an efficient and controllable manner. The proposed effort seeks to achieve the stated technical objective by designing, fabricating, and testing a special type of mechanical metamaterials in systematically stacked woodpile architectures, defined as woodpile mechanical metamaterials (WMMs). The foci of the proposed efforts are multi-fold: (i) Anderson localization: The PIs will demonstrate the combined effect of disorder and nonlinearity on Anderson localization, for the first time experimentally, in the setting of mechanical metamaterials. We will analytically, numerically, and experimentally tackle this subject by leveraging the versatility and tunability of WMMs, monitoring properties such as the second moment of the energy distribution in the media and how it temporally evolves for an initially localized wavepacket in a disordered linear, weakly nonlinear and highly nonlinear medium. (ii) Energy harvesting via mass-with-mass WMMs: The quest for long-lived localized energy in metamaterials will be of significant interest for the purpose of energy harvesting. For this, we will implement mass-with-mass features into mechanical metamaterials, such that we explore the feasibility of using nonlinear mechanical metamaterials for localizing and garnering ambient mechanical energy. (iii) Low-to-high frequency/wavenumber cascades in WMMs: Energy cascades constitute a fundamental principle in turbulent flow, in which fluidic kinetic energy is dissipated through low-to-high frequency and wavenumber conversion. Our system is dispersive rather than dissipative, yet we intend to unveil that phenomenologically analogous cascade phenomena can occur in woodpile mechanical metamaterials via resonance and anti-resonance mechanisms in our discrete nonlinear media. (iv) Controlling wave scattering in woodpile mechanical metamaterials: We also intend to explore the role of isolated metamaterial resonator defects within an otherwise homogeneous medium, via scattering experiments. These experiments characterized not only theoretically (via scattering theory) and numerically, but also experimentally, will allow us to channel, redistribute and eventually potentially trap (e.g. between two such defects) the energy, channeling controlled fractions of it towards transmission, reflection or capture. All of the above directions will be pursued simultaneously under the theme of mechanical metamaterials in the setting of not only WMM architectures, but also to the extent possible in multi-dimensional configurations.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510604
Entities
People
- Jinkyu Yang
Organizations
- Army Contracting Command
- United States Army
- University of Washington