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Creators: Mechanical and Aerospace Engineering Program
Creators: Kwon, Beomjin

Energy Absorption Properties of Standard and Origami-Inspired Honeycomb Structures

Description

The goal of this experiment was to examine the energy absorption properties of origami-inspired honeycomb and standard honeycomb structures. These structures were 3D printed with two different materials: thermoplastic polyurethane (TPU) and acrylonitrile butadiene styrene (ABS). Quasi-static compression testing was performed on these structures for both types and materials at various wall thicknesses. The energy absorption and other material properties were analyzed for each structure. Overall, the results indicate that origami-inspired structures perform best at energy absorption at a higher wall thickness with a rigid material. The results also indicated that standard honeycomb structures perform better with lower wall thickness, and also perform better with a rigid, rather than a flexible material. Additionally, it was observed that a flexible material, like TPU, better demonstrates the folding and recovery properties of origami-inspired structures. The results of this experiment have applications wherever honeycomb structures are used, mostly on aircraft and spacecraft. In vehicles with structures of a sufficiently high wall thickness with a rigid material, origami-inspired honeycomb structures could be used instead of current honeycomb structures in order to better protect the passengers or payload through improved energy absorption.

ContributorsBuessing, Robert (Author) / Nian, Qiong (Thesis director) / Zhuang, Houlong (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Watts College of Public Service & Community Solut (Contributor)

Created2022-05

Field Driven Design of Graded Cellular Structures

Description

The design of energy absorbing structures is driven by application specific requirements like the amount of energy to be absorbed, maximum transmitted stress that is permissible, stroke length, and available enclosing space. Cellular structures like foams are commonly leveraged in nature for energy absorption and have also found use in engineering applications. With the possibility of manufacturing complex cellular shapes using additive manufacturing technologies, there is an opportunity to explore new topologies that improve energy absorption performance. This thesis aims to systematically understand the relationships between four key elements: (i) unit cell topology, (ii) material composition, (iii) relative density, and (iv) fields; and energy absorption behavior, and then leverage this understanding to develop, implement and validate a methodology to design the ideal cellular structure energy absorber. After a review of the literature in the domain of additively manufactured cellular materials for energy absorption, results from quasi-static compression of six cellular structures (hexagonal honeycomb, auxetic and Voronoi lattice, and diamond, Gyroid, and Schwarz-P) manufactured out of AlSi10Mg and Nylon-12. These cellular structures were compared to each other in the context of four design-relevant metrics to understand the influence of cell design on the deformation and failure behavior. Three new and revised metrics for energy absorption were proposed to enable more meaningful comparisons and subsequent design selection. Triply Periodic Minimal Surface (TPMS) structures were found to have the most promising overall performance and formed the basis for the numerical investigation of the effect of fields on the energy absorption performance of TPMS structures. A continuum shell-based methodology was developed to analyze the large deformation behavior of field-driven variable thickness TPMS structures and validated against experimental data. A range of analytical and stochastic fields were then evaluated that modified the TPMS structure, some of which were found to be effective in enhancing energy absorption behavior in the structures while retaining the same relative density. Combining findings from studies on the role of cell geometry, composition, relative density, and fields, this thesis concludes with the development of a design framework that can enable the formulation of cellular material energy absorbers with idealized behavior.

ContributorsShinde, Mandar (Author) / Bhate, Dhruv (Thesis advisor) / Peralta, Pedro (Committee member) / Liu, Yongming (Committee member) / Jiao, Yang (Committee member) / Kwon, Beomjin (Committee member) / Arizona State University (Publisher)

Created2023

Specific Energy Absorption of Auxetic Patterns and its various applications

Description

This thesis investigates auxetic structures' specific energy absorption properties, characterized by their negative Poisson's Ratio (NPR). Auxetics, derived from natural materials and engineered designs, are increasingly applied in automotive, aerospace, and defense industries due to their enhanced material properties like indentation resistance and fracture toughness. The research commenced with a thorough literature review to gather relevant methodologies and insights into auxetic geometries. This was followed by analytical experiments and simulations focused on the re-entrant auxetic pattern, known for its simplicity and effectiveness. The study tested modifications to this pattern, aiming to enhance energy absorption by adjusting parameters like base thickness and adding filets. Simulations were performed using ANSYS 2023 R2, modeling the materials under plane stress conditions to assess their mechanical responses. Two main variants were examined: the Enhanced Stiffness pattern, which alters thickness, and the Filet Re-entrant pattern, which incorporates fillets to reduce stress concentrations. Results indicated that both modifications improved energy absorption compared to the standard re-entrant design, with Filet patterns showing superior performance due to their efficient stress distribution. This work extends the understanding of auxetic materials, demonstrating significant potential to improve safety and functionality in engineering applications through advanced material design.

ContributorsSastriawan, Yoga (Author) / Kang, Wonmo (Thesis director) / Safari, Hamid (Committee member) / Mahmoudi, Mohammadreza (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Dean, W.P. Carey School of Business (Contributor)

Created2024-05