Mechanical & Materials Engineering, Department of
First Advisor
Piyush Grover
Date of this Version
12-2023
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Mechanical Engineering and Applied Mechanics
Under the supervision of Professor Piyush Grover
Lincoln, Nebraska, December 2023
Abstract
Mechanical metamaterials built up of compliant units can support the propagation of linear and nonlinear waves. A popular architecture consists of a one-dimensional chain of bistable elements connected by linear springs. This type of chain can support nonlinear transition waves that switch each element from one stable state to the other as they propagate along the chain. One way to manipulate the propagation of such waves is via introduction of a local inhomogeneity, i.e., a defect in the otherwise periodic chain. Recent analytical and numerical work has shown that based on its initial velocity, a transition wave may be reflected, transmitted, or captured upon interaction with the defect. In this thesis, we experimentally study the nonlinear wave-defect interaction in bistable mechanical metamaterials. We produce a physical bistable chain via fused deposition modeling (FDM) additive manufacturing using polylactic acid (PLA). The defects are introduced by modifying the local stiffness and/or mass at the defect site. This work contributes towards the development of a rational approach to defect engineering for manipulating nonlinear waves.
Advisor: Piyush Grover
Included in
Materials Science and Engineering Commons, Mechanical Engineering Commons, Non-linear Dynamics Commons
Comments
Copyright 2023, Samuel R. Harre