Type
Text
Type
Thesis
Advisor
Wang, Lifeng | Alkhader, Maen | Venkatesh, T..
Date
2013-12-01
Keywords
Engineering | cellular, dynamic, honeycomb, impact, polymer, topology
Department
Department of Mechanical Engineering.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76431
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
This work investigates the dependence of strength and energy absorbance characteristics of cellular solids on inner topological features under high-strain-rate normal and mixed mode loading conditions. Topological features investigated in this work include cellular geometry, connectivity, in-plane and out-of-plane cellular aspect ratios. Varying the cellular geometry and connectivity is achieved by investigating cellular specimens with hexagonal, triangular, and square core cell geometries. This work utilizes explicit dynamic finite element simulations to examine the relationships among strength, energy absorbance, cellular geometry, and the underlying deformation mechanisms. Results over the length scales examined strongly indicate that hexagonal geometry has higher specific and overall energy absorption during all modes of loading when compared to triangular or square geometry. The controlling mechanism is identified as a combination of the number of plastic hinges present in each buckling leg and the distance between hinges (wave length). In addition, plastic hinges are found to be accountable for approximately all the absorbed energy, while the material between hinges is effectively unloaded. The way found to effectively control hinge formation is by controlling out-of-plane aspect ratio H/L. In addition to the topology-energy coupling, this work investigates the potential for enhancing the energy absorbance characteristics and capacity of cellular solids by integrating them with a polymeric matrix such that the polymer fills all cellular voids. Results show that a composite cellular-polymer system with rate-responsive polymer has the potential to be used to create highly customized energy absorbing and force-shielding material. In addition, results show that for such composite system to be effective, its constituent materials (cellular and polymer) should be of comparable compliance. | 82 pages
Recommended Citation
Brick, Vincent, "Dynamic Behavior of Cellular Architectures and the Role of Topology" (2013). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2352.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2352